The panel said Commissioner Roger Goodell did not have jurisdiction to hear the players' appeals of their punishment for their roles in the New Orleans Saints bounty program that paid cash bonuses for hits that injured opponents.
While the ruling allows Saints linebacker Vilma, banned for the 2012 season, Saints defensive end Will Smith, Cleveland linebacker Scott Fujita and free agent defensive lineman Anthony Hargrove to play immediately, it does not permanently void their suspensions.
Still, the ruling comes just two days before the first full slate of NFL games this season and is a setback for Goodell and the league.
NFL spokesman Greg Aiello said Goodell would "make an expedited determination of the discipline imposed" for violating the league's bounty rule.
"Until that determination is made, the four players are reinstated and eligible to play starting this weekend," Aiello said.
Vilma tweeted: "Victory is mine!!!! -stewie griffin"
The panel's decision states that Goodell cannot suspend the players for receiving money from a pool that paid for big plays, but he can still suspend the players if he can prove they intended to injure opponents. Players and coaches implicated in the bounty pool have testified under oath in a related federal court case they never intended to injure opposing players.
"Whether the commissioner tries to readdress the situation or not is his call," said Peter Ginsberg, Vilma's attorney. "We are certainly hoping the appeals board has made it clear the commissioner tried to grab jurisdiction and impose penalties over an area he does not have oversight. ... The factual record in the court makes it clear he has acted in a biased and inappropriate manner."
The Saints open their season at home against Washington on Sunday, while the Browns host Philadelphia.