A former Illinois State University (ISU) assistant football coach has sued the team's head coach and the school's former athletic director, alleging his First Amendment rights were violated after he removed a Black Lives Matter poster from his door and replaced it with a different one.

The suit, according to the Chicago Tribune, claims Kurt Beathard, the former offensive coordinator for ISU, was dismissed by head coach Brock Spack and terminated by former athletic director Larry Lyons in September 2020.

(Illinois State University (ISU).)

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The Tribune also reports the suit, filed earlier this week in U.S. District Court, alleges First Amendment retaliation and viewpoint discrimination against Beathard and claims he was fired because "he did not toe the party line regarding Black Lives Matter."

A protester waves a Black Lives Matter flag during a demonstration. (Stanton Sharpe/SOPA Images/LightRocket via Getty Images)

According to Beathard, a Black Lives Matter poster was placed on his door while he was on leave following the death of his wife, who had breast cancer. Once he returned to work, Beathard replaced the poster with a new one that said, "All Lives Matter to Our Lord and Savior Jesus Christ," according to the suit.

The poster remained on Beathard's door for two weeks. The poster was removed before he was fired and after Spack asked Beathard to remove it, the suit claims.

The lawsuit also alleges that Spack once referred to the Black Lives Matter movement as "freaking nuts," and that Lyons held a Zoom meeting to encourage unity during which he said, "All Redbirds Lives Matter." The school's mascot is a redbird.

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The suit noted that Lyons was forced to issue an apology for his statement and that he retired from the university roughly a month later in October 2020.

Fox News reached out to ISU about the claims made in the suit but did not receive an immediate response.