Opinion by
This case comes to us on appeal from a decision of the Court of Common Pleas of Cumberland County vacating an arbitrator’s award which ordered the reinstatement of Angelo Gallo to the position of athletic director at Cedar Cliff High School. We reverse.
Gallo is a teacher in the West Shore School District (Appellee or School District) which during the period at issue was a cosignatory to a collective bargaining agreement entered into with the West Shore Education Association (Appellantor Association). On June 13, 1979, the principal of Cedar Cliff High School informed Gallo by way of a memorandum of his intention to recommend to the School District that Gallo be removed from his extracurricular position as athletic director. In the memorandum, the principal outlined *376Ms reasons for .that recommendation. Gallo thereafter filed a grievance, contending that the memorandum was a reprimand without just cause.1 Gallo requested withdrawal of the memorandum and continuance in his position as athletic director. This grievance was taken through the procedure outlined in the contract, through the final step of arbitration. The arbitrator determined that the memorandum was a reprimand issued without just cause, that Ms removal as athletic director2 was a direct result of this unjust reprimand and .that said removal was lacking in good faith. The arbitrator ordered Gallo’s reinstatement as athletic director.
On appeal, the Court of Common Pleas, relying greatly upon this Court’s decision in Greater Johnstown Area Vocational-Technical School v. Greater Johnstown Area Vocational-Technical Education Association, 57 Pa. Commonwealth Ct. 195, 426 A.2d 1203 (1981), held that the position of athletic director was not covered by the collective bargaining agreement and therefore Gallo’s complaint was not arbitrable. The Court also determined that the “Employer’s Rights” provision of the contract3 exempted the assignment of *377teachers from arbitration and that tbe memorandum did not constitute a reprimand.
Our Supreme Gourt bas consistently reminded us of tbe very narrow scope of review given to tbe judiciary over arbitration awards. Tbe arbitrator’s decision may not be overturned so long -as it draws its “ essence” from tbe collective bargaining agreement. Leechburg Area School District v. Dale, 492 Pa. 515, 517, 424 A.2d 1309, 1312 (1981). So long as tbe subject matter of tbe dispute is encompassed witbin tbe agreement, tbe validity of tbe arbitrator’s interpretation is not a proper subject for review. Id. Furthermore, tbe broad deference given to tbe arbitrator’s decision applies equally to bis determinations regarding .tbe arbitrability of tbe subject matter of tbe grievance. Scranton Federation of Teachers, Local 1147 v. Scranton School District, 498 Pa. 58, 65, 444 A.2d 1144, 1147 (1982). See County of Allegheny v. Allegheny County Prison Employees Independent Union, 476 Pa. 27, 381 A.2d 849 (1977).
Tbe first issue we shall discuss is tbe Common Pleas Court’s ruling .that dallo’s position as athletic *378director was not covered by .the bargaining agreement. Appellant contends that this issue regarding arbitrability was not raised before the arbitrator and .therefore was waived. We .agree. While we have found no case law in our jurisdiction on this point, we would note that Section 7314(a) (1) (v) of the Uniform Arbitration Act, 42 Pa. C. S. §7314(a) (1) (v) requires the issue of the existence of an agreement to arbitrate to have been raised at the arbitration hearing before it may be considered by a court. Such a requirement comports with our well-established rule that questions not raised before a lower tribunal are deemed waived. See, e.g,, McKay v. Commonwealth, 52 Pa. Commonwealth Ct. 24, 415 A.2d 910 (1980). Appellee contends that arbitrability is a jurisdictional matter and therefore can be raised at any time. See, e.g., Department of Transportation v. Wagner, 17 Pa. Commonwealth Ct. 26, 28 n. 2, 330 A.2d 867, 868 n. 2 (1975). We cannot subscribe to such an interpretation, however; such a view would vitiate the rule of Allegheny County Prison Employees that the arbitrator’s decision on arbitrability must be given great deference.
In the present case, it is clear that the only contentions made by the School District to the arbitrator concerning arbitrability concerned compliance with the time limits of the grievance .procedure4 and arguably the bar of the “Employer Bights” section. Supra note 3. At no time before the arbitrator did the School District contend that Gallo, when acting as an athletic director, was not an employee for purposes of the collective bargaining agreement. This issue must' therefore be considered waived and thus cannot be a basis for the trial court’s decision.5
*379The Common Pleas Court also held that .the memorandum was not a reprimand for purposes of the bargaining agreement. The Court, citing to our decision in Neshaminy Federation of Teachers v. Neshaminy School District, 59 Pa. Commonwealth C.t. 63, 428 A.2d 1023 (1981),6 said that the arbitrator clearly erred in interpreting the word “reprimand” as encompassing the events here at issue. However, we believe that the trial court has given too broad a reading to the holding of Neshaminy. In Neshaminy, the arbitrator defined the issue for arbitration to be whether the grievant was dismissed for just cause where dismissal was not, by the terms of the contract, required to be for just cause. What we held in Neshaminy was that the issue framed by the arbitrator was not properly defined within the terms of the agreement. Here, the arbitrator did not frame an issue outside of the agreement; rather, the arbitrator quite clearly understood that the issue presented was whether Gallo was reprimanded for just cause, a question clearly proper under the agreement. While it may be debatable whether the principal’s actions were a reprimand, the contract gave to the arbitrator the power to handle grievances, which the contract defined as a “complaint... regarding the meaning, interpretation or application of any provision [of .the agreement].” See Greater Johnstown Area Vocational-Technical School v. Greater Johnstown Area Vocational-Technical Association, 69 Pa. Commonwealth Ct. 208, 450 A.2d 787 (1982). Since the meaning of “reprimand” was given to the arbitra*380tor to rationally define, neither we nor the trial court may inquire into the validity of .that interpretation. Leechburg.
Finally, the Common Pleas Court held that the “Employer’s Rights” provision of the contract withdrew the question of job assignments from arbitration. The Court held that “just cause” was inapplicable to assignment of duties. Initially, we note that the trial court has misconstrued the arbitrator’s decision in this case. The arbitrator fully recognized the ‘ ‘ Employer’s Rights ’ ’ provision of the contract and did not impose a just cause requirement on the exercise of those rights. Rather, after finding an unjust reprimand by the principal, the arbitrator determined that the right of assignment exercised by the School District as a result of this reprimand was not done in good faith and therefore must be overturned. See Article XIII — “The Board shall not exercise any rights in violation of this Collective Bargaining Agreement.” (Emphasis added.)
More importantly, we believe that the trial court erred in holding that this Employer’s Rights provision removes the present matter from the purview of the arbitrator. While assignment is a power reserved to the School District, the scope and extent of that power, and its applicability to this case, are not questions which go to the arbitrability of this matter, but instead are questions which go to the merits of Callo’s grievance See Scranton Federation of Teachers, Local 1147 v. Scranton School District, 66 Pa. Commonwealth Ct. 466, 445 A.2d 260 (1982). As such, they are reserved to the arbitrator and may not be ruled upon further by .the courts. Leechburg.
Order
It is ordered that the order of the Court of Common Pleas of Cumberland County, dated July 9, 1981, *381is reversed and the award of the arbitrator is hereby reinstated.