The NFL Players Association wants Vikings star Adrian Peterson reinstated immediately, claiming his suspension defied fundamental principles of notice, fairness and consistency.

The NFLPA filed a federal lawsuit Monday in Minneapolis.

The 74-page filing said NFL Commissioner Roger Goodell improperly punished Peterson because Goodell was under criticism for his handling of the incident in which NFL player Ray Rice knocked out his then-fiancée in an elevator.

Goodell "cast aside the suspended players' rights to fundamentally fair disciplinary proceedings and consistent treatment in favor of trying to demonstrate to the world that the NFL had suddenly become vigilant about player safety," the petition said.

The NFLPA petitioned the U.S. District Court in Minneapolis seeking to set aside the arbitration ruling against Peterson on Friday by Harold Henderson, the former NFL executive vice president for labor relations. Henderson ruled that Peterson must remain away from the league and all team activities until at least April 15. Peterson will be eligible to return then if he fulfills requirements set by Goodell on Nov. 18, when he suspended Peterson for the rest of the season.

The NFL did not respond to requests for comment.

The players' union faulted Goodell for retroactively applying enhanced penalties to Peterson. Had the running back been punished under the league policies in place in May, when he struck his son, he would have faced a two-game maximum suspension, the petition said.

Instead, Peterson was whipsawed in the post-Rice storm. On July 24, Rice initially was suspended for two games, the previous maximum for a first-time domestic violence offender. But when the public was not "assuaged," Goodell unilaterally — without collective bargaining — created the new policymaking a six-game suspension the presumptive sentence for a first-time domestic violence offender.

"Goodell has tried to dig his way out of the maelstrom by arbitrarily applying disciplinary measures, for purposes of public consumption, and subordinating NFL players' " collective bargaining agreement, the complaint said.

Unlike Peterson, Rice won reinstatement under an arbitrator's ruling. A retired federal judge, Barbara S. Jones, ruled in Rice's favor, holding that Goodell "lacked authority" under the union contract to impose a harsher penalty than what was in effect when the conduct occurred.

Unlike Rice, Peterson's case was heard by a "partial arbitrator," the petition said, pointing to Henderson's longtime professional relationship with the NFL executive offices.

Peterson, the NFL's MVP in 2012, is forfeiting six game checks from the 2014 season, costing him $4.1 million from his $11.75 million salary. He has played in only one game this season, the Vikings' opener at St. Louis Sept. 14. He was inactive for a second, then went on the commissioner's exempt list, with pay, for eight games. He was indicted on a felony child abuse charge on Sept. 11 in Texas.

Goodell suspended Peterson Nov. 18 following his no contest plea in Texas to a misdemeanor charge of reckless assault. He had been indicted by a Texas grand jury in September on a felony charge after injuring his then-4-year-old son by whipping him with a switch, a tree branch with the leaves removed.

The union also pointed out in Monday's court filing, as the Peterson camp has done for some time, that NFL Executive Vice President for Football Operations Troy Vincent said in a telephone conversation on Nov. 12 with the running back that he would only be punished with "time served" on the exempt list plus a two-game suspension. The two talked six days before Peterson's no-contest plea.

Also Monday, ABC News aired what it said was audio from that telephone conversation.

Peterson: "I get two games."

Vincent: "Yeah. … So, really, it's just next week … and you open, you back."

Peterson: "So, two games."

Vincent: "Yeah … you just have to go through the process."

Vincent then said to Peterson that "in my heart I'm praying that we can just get your family restored and get you back on this field so that you can continue to be the ballplayer, the citizen, the father, the husband that God's called you to be. … You've paid the price."

Vincent told the arbitrator that the telephone conversation was not a promise about what Peterson's punishment would ultimately be.

No hearing has been scheduled on the petition, which was assigned to U.S. District Judge David Doty, who has a long history of ruling on NFL matters. In 1993, Doty brought 28 millionaire owners and 1,600 football players into a room and told them to settle a labor dispute by threatening court-ordered regulation of NFL business, including free agency.

The judge sent Peterson's case, for now, to U.S. Magistrate Janie S. Mayeron. She hasn't scheduled a hearing.

Star Tribune staff writers Paul Walsh and Matt Vensel contributed to this report.