Former San Francisco 49ers safety Eric Reid has filed a collusion grievance against the NFL, reports ESPN.com's Dan Graziano.
Reid will be represented by Mark Geragos, who is also the attorney for Reid's former teammate Colin Kaepernick.
Reid has previously said he believes he could be looking for a job because of his protests.
The 26-year-old Reid had 67 tackles and two interceptions for the 49ers last season and has been only one free agent visit this offseason - with the Cincinnati Bengals.
"The notion that I can be a great signing for your team for cheap, not because of my skill set but because I’ve protested systemic oppression, is ludicrous. If you think is, then your mindset is part of the problem too," he tweeted.
Kaepernick was the first NFL player to protest racial and social injustice in the United States when he refused to stand during the playing of the national anthem.
At the end of the 2016 season, Kaepernick opted out of his contract with the 49ers and has not been signed since.
Kaepernick filed his grievance last October against NFL owners for collusion, claiming they schemed to keep him off the football field because of his protests not his football ability.
NFL commissioner Roger Goodell and Houston Texans owner Bob McNair are among those who have been deposed in the case.