Adrian Peterson finally got a legal victory Thursday with a federal judge's reinstatement order, but the ruling was swiftly appealed by the NFL.

A daylong burst of legal activity left the star running back's status with the Vikings virtually unchanged. The team released a two-sentence statement saying Peterson's status is in the hands of the league, the players' union and the legal system.

"Adrian Peterson is an important member of the Minnesota Vikings, and our focus remains on welcoming him back when he is able to rejoin our organization," the statement said.

The action began Thursday morning with a 16-page ruling from Minneapolis-based U.S. District Court Judge David Doty siding with Peterson and the NFL Players Association, saying NFL Commissioner Roger Goodell lacked authority to suspend the running back for more than two games.

Goodell had suspended Peterson in December for at least the rest of the season. After an NFL-selected arbitrator upheld that suspension, the NFLPA filed the federal lawsuit that resulted in Thursday's ruling.

NFLPA executive director DeMaurice Smith hailed the ruling as "a victory for the rule of law, due process and fairness." Doty's order sided squarely with the NFLPA's arguments, giving no traction to the NFL's position on anything.

In response, the NFL did two things: It put Peterson back on the commissioner's exempt list, where he spent most of last season, and filed notice of an appeal to the Eighth U.S. Circuit Court, based in St. Louis.

"We believe strongly that Judge Doty's order is incorrect and fundamentally at odds with well-established legal precedent governing the district court's role in reviewing arbitration decisions," the league's statement said.

Peterson's legal troubles started in May 2014 when he whipped his 4-year-old son with a switch while the boy was visiting him in Texas. He was indicted by a Montgomery County, Texas, grand jury in September — just days after Goodell suspended for a second time Baltimore Ravens wide receiver Ray Rice for knocking out his fiancée.

The Vikings immediately benched Peterson for a game, then briefly reinstated him before he was put on the exempt list, meaning he was sidelined but paid while his legal case played out.

After Peterson pleaded no contest to a misdemeanor child endangerment charge in November, Goodell suspended him and fined him six games' pay. He also ordered Peterson to receive counseling from an NFL-selected therapist.

Caught in a 'firestorm'

Doty found that Goodell went too far by applying to Peterson the enhanced personal-conduct policy adopted in the aftermath of the Rice matter. "It is undisputed that under the previous policy, first-time offenders faced a likely maximum suspension of two games," the judge wrote.

He cited Goodell's own words that "the policy change was forward-looking because the league is 'required to provide proper notice,' " to players. However, Doty said, "just two weeks later, the commissioner retroactively applied the new policy to Peterson."

Doty noted that the "public and the media excoriated" Goodell for his perceived leniency against Rice and that Peterson was caught up in the ensuing "firestorm."

An arbitrator eventually reinstated Rice. Doty's ruling said that Rice's arbitration officer "unequivocally recognized that the new policy cannot be applied retroactively, notwithstanding the commissioner's broad discretion in meting out punishment."

Peterson played only one game for the Vikings last season. His uncertain future with the team remains, although Thursday's events mean team officials can communicate directly with him rather than going through his agent, Ben Dogra. Peterson did not respond to request for comment Thursday.

Peterson's contract runs through the 2017 season. His salary for the 2015 season is $12.75 million, and the Vikings face an associated $15.4 million salary cap hit. When the new league season begins March 10, the Vikings could officially trade Peterson. They could also ask to rework his contract or cut him before then.

In the NFLPA lawsuit, filed in December, the union asked for a quick resolution so Peterson, who turns 30 next month, can resume his career. The league's case at the Eighth Circuit Court of Appeals is likely to drag on past the first day the NFL says Peterson would be eligible for reinstatement, which is April 15.

Staff writer Matt Vensel contributed to this report. Rochelle Olson • 612-673-1747