The National Football League Players Association may be preparing to challenge the NFL’s new national anthem policy in court.

The plan comes about five weeks before training camp opens and 84 days before the start of the NFL regular season, again threatening to change the focus from football to player protests.

NBC’s Pro Football Talk blog reports that the NFLPA has retained multiple law firms to look at its options. The new policy, instituted without consulting the association, requires that players stand at attention during the anthem or remain in the locker room

The potential legal challenge could be initiated under the form of a “non-injury grievance” contained in the Collective Bargaining Agreement. That grievance would have a late July deadline. The grievance would claim the NFL did not negotiate with the association before taking away a right previously enjoyed by the players.

Players previously had the right to do as they pleased during the anthem, with the league merely suggesting that they “should” stand. That started to become a problem In 2016, when former San Francisco 49ers quarterback Colin Kaepernick began sitting during the anthem. He was joined last year by multitudes of players who kneeled, raised a fist, or sat during the national anthem, creating a schism between the league and players. Sponsors, advertisers and fans also joined in the debate, creating a season-long headache for the league that overshadowed the game.