JERRY E. SMITH, Circuit Judge:
ExxonMobil Refining & Supply Company (“Exxon”) appeals a decision sending to arbitration a grievance filed by the Paper, Allied-Industrial, Chemical and Energy Workers International Union Local No. 4-2001 on behalf of Elizabeth Salinas. We affirm.
I.
In January 2001, Exxon transferred Salinas to the Clerical Unit as a Senior Administrative Assistant because her medical condition had caused her to become unable to perform the duties of her former Instrument Technician position. In late January 2003 Salinas was sent home after being informed that Exxon would no longer accommodate her medical restrictions; in March 2003 she was notified that she would not be permitted to return to work.
That same month, the union filed a grievance alleging that her discharge was based on a “disability discrimination.” The union amended the grievance in April 2003 to allege a termination for unjust cause.
The union requested that the grievance be sent to arbitration because the termination violated Article VI of the Collective Bargaining Agreement (“CBA”), which provides that the employer may discharge and discipline employees for just cause. Article XXI states that an unsuccessful
grievance that involves an alleged violation of a specific provision of the CBA must be submitted to arbitration.
Exxon denied arbitration, contending that Salinas was not discharged pursuant to Article VI but instead received a disability separation necessary to receive long-term disability benefits. The union then sued to enforce the arbitration provision of the CBA.
The district court compelled arbitration, reasoning that on its face the claim that the termination was not for just cause is arbitrable. The court added that there was no evidence supporting Exxon’s characterization of Salinas’s discharge as a challenge to a disability determination, such as evidence that she had received a disability separation.
Exxon appeals, contending that the district court erred by (1) applying the “rational mind” standard of procedural arbi-trability and (2) ignoring “most forceful evidence” that the parties did not intend disability determinations to be subject to the arbitration provision of the CBA
{e.g.
ignoring evidence with respect to arbitra-bility from the renegotiation of the Disability Plan and ignoring the fact that the Side Agreement with respect to Salinas superseded the CBA and did not provide for arbitration).
II.
We review
de novo
an order compelling arbitration.
Gen. Warehousemen & Helpers Union Local 767 v. Albertson’s Distrib., Inc.,
331 F.3d 485, 487 (5th Cir.2003). Therefore, we need not discuss Exxon’s first issue on appeal, which is that the district court used the “rational mind standard” of procedural arbitrability instead of the standard for substantive arbitrability.
“The courts’ role is very limited when deciding issues of arbitrability.”
Oil, Chem. & Atomic Workers’ Int’l Union, Local 4-447 v. Chevron Chem. Co.,
815 F.2d 338, 343 (5th Cir.1987). The court’s function is to decide whether the claim asserted is the type of claim the parties have agreed to arbitrate.
Id.
In no way are the courts to consider the merits of a claim.
Id.
Rather, the court “is confined to ascertaining whether the party seeking arbitration is making a claim which on its face is governed by the contract.”
United Steelworkers of Am. v. Am. Mfg. Co.,
363
U.S. 564, 568, 80 S.Ct. 1343, 4 L.Ed.2d 1403 (1960).
An “order to arbitrate the particular grievance should not be denied unless it may be said with positive assurance that the arbitration clause is not susceptible of an interpretation that covers the asserted dispute.”
Warrior & Gulf,
363 U.S. at 582-83, 80 S.Ct. 1347. Doubts should be resolved in favor of coverage.
Id.
That presumption is successfully rebutted only if the party resisting arbitration shows either (1) the existence of an express provision excluding the grievance from arbitration or (2) the “most forceful evidence” of a purpose to exclude the claim from arbitration.
Commc’ns Workers of Am. v. Southwestern Bell Tel. Co.,
415 F.2d 35 (5th Cir.1969).
A.
With respect to its second issue on appeal, Exxon relies on
Pac. Northwest Bell Tel. Co. v. Commc’ns Workers of Am.,
310 F.2d 244 (9th Cir.1962), to argue that evidence of bargaining history can be “most forceful evidence” that a particular dispute is not arbitrable. In this circuit, however, evidence of bargaining experience can be introduced only where the contract language is
ambiguous
as to arbitrability:
Accordingly, in this circuit the courts must construe the “language of the contract as finally agreed upon ... in accordance with ordinary rules of construction
without reference to the give and take of the bargaining sessions
which produced the final terminology. Otherwise we would abandon completely the parol evidence rule when dealing with this type of contract.”
NLRB v. Gulf Atl. Warehouse Co.,
[291 F.2d 475 (5th Cir.1961)] .... Only where the contract claim and its relationship to the written contract
is vague or unclear
is such an inquiry permissible, and then not to alter or vary the plain meaning of the contract but merely to understand the exact setting in which it was consummated.
Southwestern Bell,
415 F.2d at 40-41 (emphases added).
In
Southwestern Bell,
we expressly referred to — and implicitly
rejected
— Pacific
Northwest Bell
inasmuch as it states that “[t]he very nature of a collective bargaining agreement requires that it be read in the light of bargaining history.” We noted that “the courts must construe the ‘language of the contract as finally agreed upon’ ... without reference to the give and take of the bargaining sessions” and held that bargaining evidence cannot be introduced when there is no doubt that the arbitration clause covers the dispute at issue.
In
Southwestern Bell,
we further explained that the union’s claim that operation of the retirement provisions of the Company’s Employee Benefit Plan infringed seniority rights protected by the CBA was a “claim which on its face is governed by the contract,” and which obviously raised questions regarding the interpretation and application of a contract provision.
Id.
Additionally, we rejected the employer’s argument “that it is but a ‘subterfuge’ to characterize the Union’s claim as arising under the seniority provisions of the contract, the claim actually being one under the Employee Benefit Plan, and thus non-
arbitrable unless specifically designated.”
Id.
at 39-40. We noted that though “the Plan and its application certainly are incidentally involved in this dispute, the Union’s claim is not predicated upon any denial of rights provided under the Plan, but rather
upon the alleged infringement of contract rights by its operation,”
which was, “unquestionably” an arbitrable issue.
Id.
at 40 (emphasis added).
The union’s claim that Salinas’s termination was for unjust cause is a claim that is arbitrable on its face because it requires interpretation of the CBA (Article VI, providing that an employee can be discharged for just cause). Also, as in
Southwestern Bell,
although the claim may implicate a Benefit Plan, it is not a “disguised” Benefit Plan claim, because the union’s claim “is not predicated upon any denial of rights provided under the Plan.” Rather, it is premised on the alleged infringement of contract rights — either by the Plan’s operation or by discrimination (if the Plan was used as a pretext to discharge Salinas).
In other words, Salinas is claiming that her termination was not for “just cause;” she is not asserting that it was unwarranted under the Disability Plan. Therefore, her dispute is unambiguously arbitrable on its face, and evidence of bargaining history cannot be introduced.
B.
Exxon nonetheless argues that, for two reasons, we should not rely on
Sowthwest-em Bell.
First, it claims that
Southwestern Bell
was overruled by
AT&T Techs., Inc. v. Communications Workers of America,
475 U.S. 643, 649, 106 S.Ct. 1415, 89 L.Ed.2d 648 (1986). This argument is tenuous.
The majority opinion in that case, written by Justice White for a unanimous court, did not address whether bargaining history can be most forceful evidence of an intent to exclude a dispute from arbitration. The issue instead was whether the court or the arbitrator should decide whether the dispute over the layoff provision was arbitrable. The court of appeals had held that whether the dispute over the layoff provision was arbitrable was an issue for an arbitrator to decide. The Supreme Court disagreed, explaining that absent an express clause in the contract that provides that arbitrability questions are to be decided by an arbitrator, the arbitrator cannot decide the scope of his own jurisdiction.
Thus, the holding of
AT&T
does not reach the issue of whether evidence of bargaining history can be most forceful evidence of an intent to exclude a dispute from arbitration. Rather, the Court expressly declined to reach the arbitrability issue, because the lower court, which had sent that issue to arbitration, had not ruled on it.
Although the three-Justice concur
rence in
AT&T
did indicate that a dispute may not be arbitrable when the party opposing arbitration “adduces ■ ‘the most forceful evidence’ to this effect from the bargaining history,”
id.
at 655, 106 S.Ct. 1415, the concurring Justices did not go so far as to declare that extrinsic evidence can be introduced where the contract is unambiguous.
We find no indication in the Supreme Court caselaw cited by Exxon that would allow introduction of “most forceful” extrinsic evidence even if the contract is unambiguous. The decision that introduced the concept of allowing “most forceful evidence” to demonstrate an intent to exclude a dispute from arbitration involved a “vague” (not unambiguous) provision. In that case, the Management Function clause purportedly excluded the dispute at issue from arbitration.
Therefore, the discussion in
Warrior & Gulf
of allowing introduction of extrinsic evidence does not address, at all, the issue of whether such evidence could be introduced when the contract is unambiguous. Unlike in
Warrior & Gulf
there is no ambiguity in this case.
Nor is there any clause in the CBA, vague or otherwise, that would introduce any doubt as to whether disputes allegedly violating Article VI are arbitrable. Exxon rejected the union’s arbitration demand on the ground that arbitration of a claim with respect to Salinas’s termination would violate Article XVII(A) of the CBA, which provides that the CBA does not affect the eligibility of employees to participate in the Benefit Plans (including the disability plan).
If this argument were correct, Article XVII(A) would qualify as an express provision in the CBA excluding certain types of grievances from arbitration and could render this dispute non-arbitrable.
But this reasoning is illogical: By its terms, the union could never arbitrate a discharge, such as a discharge for racial or other discrimination, because reinstatement of a discharged employee would make him again qualify for benefits, which would “of necessity” affect his eligibility to participate in the Benefit Plan. This would in effect nullify Article VI.
Furthermore, Article XVII(A) does not mention arbitration. It is unlike the exclusionary clause at issue in
Southwestern Bell,
which expressly excluded claims relating to Benefit Plans from arbitration. It is also unlike the Management Function clause in
Warrior & Gulf.
Last, as we explained in
Southwestern Bell,
the Court in
Warrior & Gulf
declined to address the issue of whether bargaining evidence could ever be admissible to show whether an issue was. excluded from arbitration:
Though some disagreement exists among the circuits on the admissibility of evidence of bargaining history to show whether an issue was excluded from arbitration ..., the rule in this circuit has been clear since the Supreme Court’s opinion in
[Warrior & Gulf],
where the majority, faced with having to determine whether an exclusionary clause^ prevented arbitration of a sub
contracting grievance, refused even to mention bargaining history that showed repeated unsuccessful attempts by the Union to secure contractual restrictions on subcontracting.
Southwestern Bell,
415 F.2d at 40 (citations omitted). Therefore, unless and until the Supreme Court addresses the issue of whether bargaining history is admissible to modify the terms of an unambiguous contract,
Southwestern Bell
is good and binding law in this court.
C.
The second argument Exxon makes in its attempt to minimize the precedential effect of
Southwestern Bell
is even more far-fetched than is its reliance on the concurrence in
AT&T.
Exxon contends that
the Fifth Circuit characterized
Southwestern Bell’s
limited exception to the parole-evidence rule as dictum, and rejected the company’s arbitrability argument, in part, because it offered “no extrinsic evidence
stick as bargaining history”
to support its interpretation.
IBEW v. Western Electric Co.,
661 F.2d 514, 516, n. 4 [(Former 5th Cir. Nov. 1981)].
(Emphasis added.)
But, as is evident from a reading of
South-westem Bell,
the
dictum
there regards the
permission
to introduce bargaining evidence when the contract is
ambiguous,
not the
prohibition
to introduce such evidence when the contract is
unambiguous:
Only where the contract claim and its relationship to the written contract is [sic] vague or unclear is such an inquiry [into bargaining history] permissible, and then not to alter or vary the plain meaning of the contract but merely to understand the exact setting in which it was consummated .... But this narrow exception to the general rule of exclusion
is not operative here,
where both the nature of the Union’s claim and the meaning of the collective agreement
are evident
....
Southwestern Bell,
415 F.2d at 40-41 (footnote omitted).
This court in
Southwestern Bell
had in fact actually held that evidence of bargaining history is not admissible where the contract is unambiguous, which is precisely the issue here. Therefore this could not have been
dictum
regardless of how we described it in
Western
Electric,
Accordingly, Exxon’s attempt, at oral argument and in its reply brief, to characterize
Southwestern Bell
as inapposite is misguided.
Furthermore, in
Western Electric
we did not address
Southwestern Bell’s
holding, but only its
dictum
that allowed introduction of bargaining evidence when the contract was “ambiguous.” In
Western Electric,
the employer conceded that the dispute over each of the forty employees’ classifications was arbitrable, yet the employer contended that the use of the term “an employee” manifested an intent to submit to arbitration only issues involving one employee at a time, not an intent to submit to “group arbitration.” We explained that the contract did not unambiguously provide the interpretation that the employer suggested; we stated that if the company intended the words “an employee” to have such an effect, “it had to make its understanding much clearer than this.”
Western Elec.,
661 F.2d at 516-17.
Therefore, there was an ambiguity as to the effect of the term “an employee.” We then noted that although the
dictum
in
Southwestern Bell
allows introduction of evidence of bargaining history when the contract is “ambiguous,” the employer in that case did not introduce any such evidence.
Id.
at 516. Thus, absent any extrinsic evidence against arbitration, and given the presumption in favor of arbitra-bility, we resolved the doubt in favor of arbitration.
Western Electric
is thus inapposite not only because it did not reject
Southwestern Bell,
but also because, as in the
Southwestern Bell dictum,
it allowed introduction of bargaining history and other extrinsic evidence where the contract was ambiguous. In contrast, the contract here
unambiguously
covers disputes relating to the interpretation of the “just cause” discharge provision of the CBA.
Last, Exxon argues that
NLRB v. L.B. Priester & Son, Inc.,
669 F.2d 355 (5th Cir.1982), also supports its argument in favor of allowing the introduction of bargaining evidence. That decision, however, is not inconsistent with either the holding or the
dictum
in
Southwestern Bell.
In that case, as Exxon admits, we “upheld the NLRB’s affirmation of an ALJ’s reliance on extrinsic evidence to shed light on an
ambiguous
CBA provision.” Exxon Reply Br. at 2 (emphasis added). Again, unlike the contract in this case, the contract there was “ambiguous,” so introduction of bargaining evidence was permissible under the
dictum
in
Southwestern Bell.
Most importantly, that case did not address whether the introduction of bargaining history would be permissible if the contract were not ambiguous.
D.
Other courts, as well, have held that unless the CBA provides instances of what constitutes “just cause” and expressly provides that discharges based on those instances are not arbitrable, the question whether an employee was discharged for just cause is arbitrable. Where the CBA prohibits discharge of regular employees “ ‘except for just cause,’ and does not define ‘just cause,’ ” and “where the CBA authorizes the arbitrator to resolve disputes concerning the interpretation or application of its terms, it remains for the arbitrator to determine whether a discharge was for ‘just cause.’ ”
First Nat’l Supermarkets, Inc. v. Retail, Wholesale & Chain Store Food Employees Union Local 338,
118 F.3d 892, 896-97 (2d Cir.1997). If the employer “wished to have an unquestionable right to discharge an employee for any specified conduct, it needed to negotiate for recognition of that right in the CBA.”
Id.
at 896.
Similarly in this case, if Exxon wished to have an unquestionable right not to submit to arbitration discharges that allege “unjust cause” but touch matters relating to a disability termination, it could have provided that (1) a long-term disability termination constitutes a discharge for just cause and (2) discharges that are made for a reason that is defined as “just cause” are not arbitrable.
Exxon is free to argue to the arbitrator that the disability was the cause, not the pretext, of the termination and that Salinas’s termination was for just cause.
III.
Even if bargaining evidence were admissible, the bargaining evidence in this case is not most forceful evidence showing a purpose to exclude this dispute from arbitration. The bargaining history refers to the employer’s refusal to arbitrate disability decisions and benefit levels under the Plan. But the union is making a “disability discrimination” argument for the discharge, which is not a claim of whether the Benefit Plan was applied correctly, but whether the company discriminated against Salinas because of her disability. The March grievance specifically alleges a discharge based on a “disability discrimination” and alleging violation, among others, of Articles II (discrimination) and VI (just cause discharge). The April amended grievance alleges a violation of the just cause termination provision.
Thus, even if the bargaining history had proved that the parties did not intend disability determinations to be arbitrable,
and assuming
arguendo
that there was evidence in the record showing that Salinas received a disability termination, a claim that the company discriminated against an employee and unjustly terminated him because of his disability is, as we explained in
Southwestern Bell,
only “incidentally” related to a disability determination.
Although the disability determination, if correct, will help the arbitrator in deciding the merits of the “unjust termination” claim, it is not at the heart of a discrimination/“unjust cause” termination grievance, which is predicated on the motives of the company in making that decision. That is, merely because Exxon asserts a defense based on a non-arbitrable issue does not render non-arbitrable a claim that was ar-bitrable when asserted.
Further, if the court were to decide the frivolousness of the defense in deciding arbitrability (e.g. was the disability determination a “pretext” or was it correct), the court in effect would be deciding the merits of the case; as we have explained, this is not permitted, because the parties have reserved the merits of the case to the arbitrator.
In sum, the bargaining history does not present any evidence that disputes alleging unjust termination (rather than contesting a disability termination) are non-arbitrable just because the employee was disabled. Exxon presented no evidence of bargaining history or an express contractual provision showing that the parties wished to exclude from arbitration claims related to discrimination discharges.
IV.
Exxon claims that the Side Agreement with respect to Salinas superseded the CBA and, because it does not provide for arbitration, this dispute is not arbitrable. But this argument fails precisely because the Side Agreement is silent with respect to arbitration. That is, that agreement does not provide that any grievance that Salinas may file related to a possible future discharge cannot be submitted to arbitration. If Exxon intended that the Side Agreement supersede the CBA with respect to the arbitration issue, it could have provided for that expressly.
Our decision in
Int’l Union of Operating Eng’rs, Local 351 v. Cooper Natural Res., Inc.,
163 F.3d 916, 919 (5th Cir.1999), and the other cases on which Exxon relies, are distinguishable because in those cases, the later-in-time last chance agreements (LCA’s) were not silent as to the issue on which they allegedly superseded the CBA. Under the CBA, a drug offense did not automatically result in a discharge. In contrast, the LCA’s expressly included clauses that reduced the benefits awarded by the CBA, providing that any future similar offenses (usually drug offenses) would automatically result in discharge. In contrast, the Side Agreement does not provide that Salinas may be discharged at any time without any recourse to arbitration.
Further, the Side Agreement does not even provide that Salinas can be discharged (with or without arbitration) if her medical restrictions will prohibit her from meeting her obligations as a Senior Administrative Assistant. Instead, it states only that in that circumstance “she will be medically evaluated and her restrictions reviewed.”
“Reviewed” does not mean “automatically discharged.” It does not exclude a possibility that Salinas could be transferred to a less “senior” position in the Clerical Unit, because, as the Side Agreement recognizes, Salinas passed the “Staff Support Test and is qualified to work” in that unit. Therefore, there is no indication in the Side Agreement that Salinas would be automatically discharged if her condition worsened and she were medically evaluated.
In any event, the issue of whether the discharge was appropriate was still arbi-trable in the cases on which Exxon relies. In those, cases, the court merely reviewed the arbitral award and held that the arbitrator could not fashion “other relief’ if the LCA provided that, in case of a discharge for a drug offense, there will be no reinstatement.
Cooper,
163 F.3d at 919. Those courts did not state that a discharge for a future drug offense will be non-arbitrable.
AFFIRMED.