The NFL Players Assn. filed a grievance with the NFL on Monday to reinstate Minnesota Vikings running back Adrian Peterson.
Peterson, who agreed in September to be placed on the commissioner's exempt list, pleaded no contest last Tuesday in Texas to a charge of misdemeanor reckless assault. He had faced a more serious charge of felony child abuse stemming from an incident when he punished his 4-year-old son by whipping him with a tree switch.
The NFL began a review of Peterson's case on Thursday under the terms of the league's personal-conduct policy and said he will remain on paid leave until the process is completed.
The NFLPA said in a statement it wants Peterson cleared to return immediately based on "explicit language in a signed agreement" with the league.
"We asked the NFL to honor the terms of that agreement last week and as of now, they have failed to respond or comply," the union said in a written statement. "It is our obligation to protect all players' rights, and we will pursue any and all breaches of any contract between a player and his team or the NFL."
Vikings Coach Mike Zimmer said Monday the team wants Peterson back right away but that the club's "hands are tied" because the decision belongs to NFL Commissioner Roger Goodell.