A federal judge has cleared the way for Minnesota Vikings running back Adrian Peterson to be reinstated, ruling that an NFL arbitrator "failed to meet his duty" in a child abuse case that shook the league.

U.S. District Judge David Doty issued his order on Thursday, less than three weeks after hearing oral arguments. Doty overruled NFL arbitrator Harold Henderson's denial of Peterson's appeal.

The league suspended Peterson through at least April 15 under its personal conduct policy. But Doty said in his 16-page ruling that Henderson "simply disregarded the law of the shop, and in doing so failed to meet his duty" under the collective bargaining agreement.

NFL spokesman Brian McCarthy said the league will "review the decision."

NFL Players Association executive director DeMaurice Smith said in a statement the decision was a "victory for the rule of law, due process, and fairness."

The crux of the issue was the application of the enhanced personal conduct policy, increasing a suspension for players involved with domestic violence from two games to six games. Because that was implemented after the injuries occurred to Peterson's son, delivered by a branch that Peterson was using for discipline, the union contended that the prior standard of punishment should apply.

"This is yet another example why neutral arbitration is good for our players, good for the owners, and good for our game," Smith said.

Now there's the matter of Peterson's future with the Vikings.

He's under contract through 2017, carrying a $15 million salary cap hit for 2015, and several high-ranking Vikings officials have said definitively they want him to return. General manager Rick Spielman said last week he expects Peterson to be back. But Peterson has expressed some uneasiness, telling ESPN in a recent interview he felt betrayed by the organization while on paid leave.

The market opens on March 10, at which time the Vikings could trade Peterson. If they cut him, they'd owe him no more money and take only a $2.4 million hit to their salary cap.