Dallas Cowboys running back Ezekiel Elliott's six-game suspension for violation of the NFL's domestic-violence policy was upheld by league arbitrator Harold Henderson on Tuesday.
However, Elliott reportedly will be eligible to play Sunday in Week 1 against the New York Giants due to the timing of Henderson's announcement.
Elliott's legal team said in a statement: "We are extremely disappointed with Mr Henderson's inability to navigate through league politics, and follow the evidence and, most importantly, his conscience."
The NFL Players Association previously filed a restraining order seeking to block any suspension for Elliott, and a judge is due to rule on by 5 p.m. CDT on Friday.
The NFLPA's case is centred around its argument that the league violated its own disciplinary process under the collective-bargaining agreement.
If the order is granted, Elliott would be allowed to continue playing while his federal case works its way through the legal system.
If denied, Elliott would begin serving his suspension with the Dallas Cowboys' game against the Denver Broncos in Week 2, on September 17.
On Monday, the NFL filed a motion to have the NFLPA's restraining-order request dismissed.
"The NFLPA claims that it is likely to succeed in its claim that the underlying proceeding was 'fundamentally unfair' in light of certain procedural and evidentiary rulings by the Arbitrator," the NFL's motion reads.
"But this is hardly the first time the NFLPA has made this argument. Courts around the country have consistently and squarely rejected it, along with every other attempt by petitioners to second-guess arbitration decisions upholding NFL player discipline."
Elliott, who was not arrested nor charged in the case, maintains his innocence after being accused of assaulting his former girlfriend, Tiffany Thompson. The original punishment was issued by NFL commissioner Roger Goodell on August 11 after a 13-month investigation.
Elliott, the fourth overall pick in the 2016 draft, led the NFL in rushing with 1,631 yards during his rookie season.