Adrian Peterson will not play NFL football this season. The star running back who was accused of abusing his son earlier this year had his appeal denied by an independent arbitrator, the NFL announced Friday.

Peterson, 29, was indicted in September by a Texas grand jury after prosecutors alleged that he beat his 4-year-old with a tree branch, causing graphic injury to the boy’s back, genitals and legs. He pleaded no contest and will avoid jail time, though the NFL determined that he violated the league’s personal conduct policy.

The NFL Player’s Association argued that, by suspending Peterson without pay for at least the rest of the season, NFL Commissioner Roger Goodell applied inconsistent and unfair treatment. Yet Harold Henderson, a former league executive who was appointed as an independent arbitrator to hear Peterson’s appeal, determined that the player “had not demonstrated that the process and procedures surrounding his discipline were not fair and consistent,” as quoted by ESPN.

“He was afforded all the protections and rights to which he is entitled, and I find no basis to vacate or reduce the discipline,” Henderson went on. reporter Ian Rapoport tweeted that the expectation now is that Peterson’s camp will take the case to federal court. The union implied that would be the case in a statement issued moments after the decision was announced.

“The NFLPA expected this outcome, given the hearing officer’s relationship and financial ties to the NFL,” the statement said. “The decision itself ignores the facts, the evidence and the collective bargaining agreement. This decision also represents the NFL’s repeated failure to adhere to due process and confirms its inconsistent treatment of players. Our union is considering immediate legal remedies.”

Goodell has previously said that he will not consider reinstating Peterson until April 2015 at the earliest.