MINNEAPOLIS — A federal magistrate ordered the NFL and the NFL Players Association into settlement negotiations Monday in their fight over Adrian Peterson’s suspension.

U.S. Magistrate Judge Janie Mayeron set a settlement conference for Aug. 13. That is the same day U.S. District Judge David Doty has scheduled a hearing on the NFLPA’s contempt-of-court motion against the league and Commissioner Roger Goodell, for not complying with Doty’s order to send Peterson’s disciplinary matter back to the NFL arbitrator.

The hearing in Doty’s chambers was delayed until after the settlement conference, union spokesman George Atallah said. Both Atallah and NFL spokesman Brian McCarthy declined to comment on the order, but Mayeron spelled out her expectations tersely.

“All participants should plan on spending the entire day and evening, if necessary,” she said.

She ordered both sides to discuss a settlement on or before July 30 and if nothing comes of that to give her confidential letters outlining their positions by Aug. 6.

Noncompliance with the order, Mayeron wrote, could lead to “an appropriate sanction.”

Peterson was punished by the league for a child abuse charge he faced in Texas regarding his young son. His discipline was essentially a six-game suspension, but he was sidelined for nine games before that on paid leave while the child abuse case moved through the legal system.

The NFLPA filed a petition last Dec. 15, seeking a rejection of NFL arbitrator Harold Henderson’s decision to deny Peterson’s appeal of his suspension.

Doty sided with the union in his ruling issued Feb. 26, and the league appealed. The NFL asked the 8th U.S. Circuit Court of Appeals in its initial filing April 8 to overturn Doty on the grounds he didn’t have authority to usurp a case the league argued should be limited to a labor dispute and thus fell under the umbrella of the collective bargaining agreement.

Goodell reinstated Peterson on April 16, rendering any re-arbitration process moot in terms of the star running back’s playing status. But the issue has stayed alive in court, with both sides remaining at odds over fairness and administration of the NFL’s personal conduct policy.

On May 19, the NFLPA filed its motion to hold the NFL and Goodell in contempt of court, alleging the league “deliberately ignored” Doty’s decision and the union’s repeated subsequent requests to comply by forcing Henderson to reconsider his decision.

Peterson was initially reticent toward returning to the Vikings, but he softened his stance and rejoined his teammates for practice on June 2. The Vikings report for training camp on Saturday.