Former San Francisco 49ers quarterback Colin Kaepernick has filed a grievance against the NFL, claiming team owners colluded to keep him out of the league because of his protests during the national anthem before games.
The NFL did not respond to ABC, who reached out for comment on the story.
The suit alleges that the league's owners "colluded to deprive Mr. Kaepernick of employment rights in retaliation for Mr. Kaepernick's leadership and advocacy for equality and social justice."
Kaepernick's attorney, Mark Geragos, said in a statement to ABC the grievance was filed "only after pursuing every possible avenue with all NFL teams and their executives."
He said his goal was just to be treated fairly and to return to playing football in the NFL, "the league he performed at the highest level for."
The NFL Players Association said in a statement, "Our union has a duty to assist Mr. Kaepernick as we do all players and we will support him."
Kaepernick's protest of kneeling during the national anthem began in 2016 and it was soon mimicked by some other players. It received even more prominence last month when President Donald Trump said NFL owners shouldn't tolerate players who "disrespect our flag."
Kaepernick reached the Super Bowl with the 49ers during the 2012 NFL season and reached the playoffs again as the team's full-time quarterback in 2013. He went just 3-16 as a starter over the past two seasons on a rebuilding San Francisco team, however.
He became a free agent last year after opting out of his contract.