NEW YORK — New England Patriots quarterback Tom Brady must serve the four-game suspension imposed by the NFL in the “Deflategate” case, a federal appeals court ruled Monday, overturning a lower-court judge and siding with the league in a battle with the players union.

A three-judge panel of the 2nd U.S. Circuit Court of Appeals in Manhattan ruled 2-1 that Commissioner Roger Goodell did not deprive Brady of “fundamental fairness” with his procedural rulings. The split decision may end the legal debate over the scandal that led to months of arguments over air pressure and the reputation of one of the league’s top teams.

It also fuels a fresh round of debate over what role, if any, Brady played in using underinflated footballs in the AFC championship game in January 2015. The Patriots beat the Indianapolis Colts, 45-7, then won the Super Bowl two weeks later.

The ruling can be appealed to the full 2nd Circuit or to the U.S. Supreme Court, but it would likely be a steep and time-consuming climb even if the courts took the unusual step of considering it.

In a majority opinion written by Judge Barrington D. Parker, the 2nd Circuit said its review of labor arbitration awards “is narrowly circumscribed and highly deferential – indeed, among the most deferential in the law.”

“Our role is not to determine for ourselves whether Brady participated in a scheme to deflate footballs or whether the suspension imposed by the Commissioner should have been for three games or five games or none at all. Nor is it our role to second-guess the arbitrator’s procedural rulings,” the opinion said. “Our obligation is limited to determining whether the arbitration proceedings and award met the minimum legal standards established by the Labor Management Relations Act.”

The panel said the contract between players and the NFL gives the commissioner authority that is “especially broad.”

“Even if an arbitrator makes mistakes of fact or law, we may not disturb an award so long as he acted within the bounds of his bargained-for authority,” the court said.

In a dissent, Chief Judge Robert Katzmann said Goodell failed to even consider a “highly relevant” alternative penalty.

“I am troubled by the Commissioner’s decision to uphold the unprecedented four-game suspension,” Katzmann said. “It is ironic that a process designed to ensure fairness to all players has been used unfairly against one player.”

The NFL Players Association said in a statement that it is disappointed.

“We fought Roger Goodell’s suspension of Tom Brady because we know he did not serve as a fair arbitrator and that players’ rights were violated under our collective bargaining agreement,” the statement said. “Our union will carefully review the decision, consider all of our options and continue to fight for players’ rights and for the integrity of the game.”

NFL spokesman Brian McCarthy said the court ruled that Goodell acted properly in cases involving the integrity of the game.

“That authority has been recognized by many courts and has been expressly incorporated into every collective bargaining agreement between the NFL and NFLPA for the past 40 years,” McCarthy said.

In September, Manhattan Judge Richard Berman ruled against the league, letting Brady skip the suspension last season. Goodell insisted that the suspension was deserved.

The appeals court settled the issue well before the start of the 2016 season, avoiding the tension that built last year when Brady didn’t learn until a week before the season whether he would be allowed to start in the Patriots’ opener.

The Patriots open the 2016 season Sept. 11 at Arizona, followed by games at home against the Dolphins, Texans and Bills. Brady’s backup at quarterback is Jimmy Garoppolo, who appeared in 11 games over his first two seasons but hasn’t made a start.

In oral arguments in March, appeals judges seemed skeptical of arguments on Brady’s behalf by the NFL Players Association.

Circuit Judge Denny Chin said evidence of ball tampering was “compelling, if not overwhelming” and there was evidence that Brady “knew about it, consented to it, encouraged it.”

The league argued that it was fair for Goodell to severely penalize Brady after he concluded the star quarterback tarnished the game by impeding the NFL’s investigation by destroying a cellphone containing nearly 10,000 messages.

Parker said the cellphone destruction raised the stakes “from air in a football to compromising the integrity of a proceeding that the commissioner had convened.”

“So why couldn’t the commissioner suspend Mr. Brady for that conduct alone?” he asked. Parker added: “With all due respect, Mr. Brady’s explanation of that made no sense whatsoever.”

Parker also was critical of the NFL during the arguments, saying Brady’s lengthy suspension seemed at “first blush a draconian penalty.”