Minneapolis, MN (SportsNetwork.com) - Adrian Peterson has been reinstated after a judge on Thursday overturned the league's suspension of the Minnesota Vikings running back.

Peterson was originally charged with reckless or negligent injury to a child for striking his 4-year-old son with a wooden tree branch in May and was placed on the commissioner's exempt list in September. He was then suspended by NFL commissioner Roger Goodell in November for violating the personal conduct policy after reaching a plea agreement in Texas and the NFL Players Association filed an appeal that was upheld by league-appointed arbitrator Harold Henderson in December.

The NFLPA then filed a federal lawsuit after its appeal was denied and U.S. District Judge David S. Doty on Thursday granted the union's motion to have Henderson's ruling vacated.

"This is a victory for the rule of law, due process and fairness," the NFLPA said Thursday in a statement. "Our collective bargaining agreement has rules for implementation of the personal conduct policy and when those rules are violated, our union always stands up to protect our players' rights. This is yet another example why neutral arbitration is good for our players, good for the owners and good for our game."

Under terms of the NFL suspension, Peterson would have been considered for reinstatement as of April 15.

When filing its lawsuit, the NFLPA had maintained its stance that the NFL was "making it up as it goes along," in reference to the league's decisions on suspensions related to the personal conduct policy. The union added that the harsh punishment came as a result of the league's new personal conduct policy and that it should not be applied retroactively in Peterson's case.

The NFL said the commissioner had the "broad discretion" under the collective bargaining agreement to impose the enhanced discipline under the new policy.

Doty, however, disagreed with the NFL's assertion and said Henderson exceeded his authority in the appeal ruling.

Peterson last played in the Vikings' season opener Sept. 7. The two-time NFL rushing champion pleaded no contest to a lesser misdemeanor offense after working out an agreement with the Montgomery County (Texas) district attorney.

The 2012 NFL MVP avoided jail time and was placed on probation while receiving a $4,000 fine and an order to perform 80 hours of community service.