Colin Kaepernick is taking a stand.

The most polarizing quarterback in the free-agent pool filed a grievance against NFL owners for collusion, alleging the league “entered into an enforced, implied and/or express agreements to specifically deprive” Kaepernick of employment. The grievance also references the “Executive Branch of the United States government,” suggesting President Trump further coerced the league into keeping Kaepernick jobless.

Kaepernick filed Sunday under the collective bargaining agreement, not through the NFL Players Association, and has hired attorney Mark Geragos, according to Bleacher Report, a lawyer who has represented high-profile clients such as Michael Jackson, Winona Ryder and NASCAR driver Jeremy Mayfield.

The grievance, obtained by Yahoo Sports, argues Kaepernick is no longer in the NFL as a retaliation for his stance as the face of the national anthem movement and his “advocacy for equality and social justice and his bringing awareness to peculiar institutions still undermining racial equality in the United States.”

Further, the grievance says the owners’ revenge came in “calculated coordination” with Trump. In March, Trump took credit for Kaepernick not having a gig, bragging to a Kentucky audience about a report that said, according to Trump, “NFL owners don’t want to pick him up because they don’t want to get a nasty tweet from Donald Trump.”

Trump recently has taken a personal interest in the national anthem protesters, imploring owners to cut any “son of a bitch” who takes a knee.

Kaepernick is the originator of the movement, which he began last year to protest police brutality and the treatment of minorities in the United States. While spearheading the protest, he played effectively, if not spectacularly, with a poor 49ers team, for whom he threw 16 touchdowns and had four interceptions in 12 games.

After the season he opted out of his contract and has received little interest and zero offers from the league, which has mostly been uncertain how to handle athletes taking a knee during “The Star-Spangled Banner.”

In a league in which retread quarterbacks are recycled every year, the silence around Kaepernick has been curious, with some maintaining he’s too controversial for their fan base to touch and others stating he’s not good enough.

Giants co-owner John Mara said he got a flood of letters this offseason from fans pleading him to stay away from Kaepernick, though he denied the one-time rising star was being blackballed.

“Anybody that thinks that there’s been any conversations going on among teams about Colin Kaepernick is crazy,” Mara said on ESPN Radio in August. “That just is not the case. I saw a quote, I think it was [Dolphins owner] Steve Ross recently that said, ‘Teams want to win so badly that if they believe a player can help them win, they’re going to bring him on.’ I think there are certain issues obviously that go along with Colin Kaepernick and that may have scared some teams away, but there is absolutely no blackball going on here.I just don’t see that at all.”

At the time, Mara thought Kaepernick would find a job. It’s Week 6, and the player who brought San Francisco to the Super Bowl in 2013 is still unsigned, even as many quarterbacks have gone down.

Commissioner Roger Goodell, too, has denied the league has conspired against signing Kaepernick.

“I believe that if a football team feels that Colin Kaepernick, or any other player, is going to improve that team, they’re going to do it,” he said in June.