Two Black former N.F.L. coaches have joined a lawsuit filed in February by Brian Flores, the former head coach of the Miami Dolphins who accused the league and its 32 teams of discriminating against African Americans in their hiring practices.

On Thursday, Steve Wilks, who was fired after one season as head coach of the Arizona Cardinals, and Ray Horton, a longtime assistant coach and defensive coordinator, were added to the Flores complaint. A pretrial conference for the federal lawsuit is scheduled for April 29.

In the amended complaint, Wilks, 52, said that the Cardinals hired him as a “bridge coach” in 2018 and that he was not given any meaningful chance to succeed under a general manager, Steve Keim, who “made poor personnel decisions.”

The Cardinals finished with a 3-13 record that season. Wilks was fired before the team drafted quarterback Kyler Murray with the No. 1 overall pick in 2019. Kliff Kingsbury, who is white and had no N.F.L. coaching experience, was hired to replace Wilks.

After Wilks left Arizona, he was defensive coordinator for the Cleveland Browns in 2019 and then held the same position at the University of Missouri in 2021. In February, he was hired by the Carolina Panthers as a defensive pass game coordinator and secondary coach.

“Like Brian and Ray, I did not make the decision to join this lawsuit based on what it could potentially cost me in my own career,” Wilks said in a statement. “Instead, this decision was made to help pave the way for the next generation of talented minority coaches and executives to finally be given an equal opportunity and level playing field. When I consider that joining this call for equality could one day help a child of color who dreams of coaching an N.F.L. team, what I stand to lose becomes irrelevant.”

Ahead of the 2016 season, Horton applied for the head coaching job with the Tennessee Titans, where he was the defensive coordinator. Horton, who held assistant coach and coordinator positions with seven franchises in a 24-year career on the sideline, said in the complaint that the team gave him a “sham interview” so it could meet the Rooney Rule, a league requirement that teams consider a diverse slate of candidates for open head coaching positions.

The Titans that year promoted the interim coach Mike Mularkey, who is white, to head coach. In a podcast interview conducted four years later, Mularkey said the Titans owner Amy Adams Strunk and her family told him he would be hired before they interviewed nonwhite applicants.

“I sat there knowing that I was the coach in ’16, as they went through this fake hiring process knowing a lot of the coaches that they were interviewing, knowing how much they prepared to go through those interviews, knowing everything they could do and they have no chance at getting that job,” Mularkey said to “Inside Pro Football Podcast.” He added that it was his biggest regret in his career.

Over three seasons, Mularkey coached the Titans to a 20-21 record. Horton, 61, coached two more seasons: as defensive coordinator for the Cleveland Browns in 2016 and as defensive backs coach with Washington in 2019. Horton is still seeking work in the N.F.L., but said in the complaint that he was viewed as a “stale” candidate and that he had not been called to interview for any head coach job openings.

“When I learned from Coach Mularkey’s statements that my head coach interview with the Titans was a sham, I was devastated and humiliated,” Horton said in a statement.

He added: “Although I know that I am taking a risk being associated with this case, it would be a bigger risk to stand on the sideline and give the N.F.L. a pass for the systemic discrimination that has harmed me and so many others.”

The claims by Wilks and Horton echo allegations Flores made in his original complaint. Before being hired by the Dolphins in 2019, Flores said, he sat for what he called a “sham” interview with executives from the Denver Broncos. In that meeting, Flores said, John Elway, then the team’s general manager, and Joe Ellis, the team’s president, and others showed up an hour late. Flores felt the only reason he was interviewed was so the team could comply with the Rooney Rule, an assertion the team denied. Elway called Flores’s characterization “false and defamatory.”

After Flores was fired by the Dolphins at the end of the 2021 season, he interviewed for other head coaching positions, including with the Giants. In his original complaint, Flores said he had been “humiliated in the process as the New York Giants subjected him to a sham interview in an attempt to appear to provide a Black candidate with a legitimate chance at obtaining the job.”

Last week, a co-owner of the team, John Mara, denied the allegations and said he had no plans to settle the suit. “We’re very comfortable with our hiring process,” he said. “It was a fair process, and we ended up making the decision that we made based on a lot of factors, none of which had to do with race.”

After Flores failed to land another head coaching job this off-season, he was hired by Steelers Coach Mike Tomlin as a senior defensive assistant and linebackers coach.

The addition of two coaches to Flores’s case does not necessarily make it stronger, legal experts said. All three coaches claim they were denied jobs because the teams were only trying to meet the requirement that candidates of color be interviewed. But the N.F.L. could argue that each situation was unique, and thus should be adjudicated separately.

“There may be hundreds or at least dozens of African American candidates for various coaching jobs, but the reality is, in the absence of a policy by the N.F.L. that discriminates against coaches, it’s hard to argue that these aren’t individualized facts,” said Ted Frank, a director at the Hamilton Lincoln Law Institute and the Center for Class Action Fairness, a nonprofit public interest law firm. “Even if you find a discriminatory email from an owner, that reflects on that owner, not the whole N.F.L.”

Frank said that if the case is not certified as a class action, it could proceed as three distinct claims. The N.F.L., he added, would most likely try to push each of the cases into arbitration, as it has in other cases involving league employees, where it would be heard out of court and away from the news media.

Regardless of the legal merits, the case has shined an unflattering light on the N.F.L., which has been repeatedly accused of not doing enough to promote diversity in its coaching ranks, where just six of 32 head coaching positions are filled by nonwhite men. The Flores case is being fought while the league faces public scrutiny on Capitol Hill, where a congressional committee is looking at allegations of workplace harassment at the Washington franchise. On Wednesday, attorneys general from six states said they would begin an investigation if the N.F.L. did not address accusations of workplace harassment at the league’s head office.

Meanwhile, the league has unveiled efforts to ensure diverse candidates are considered for top jobs. At its annual meetings last week, the N.F.L. announced an expansion of the Rooney Rule to stipulate that each team with open head coach and general manager jobs must conduct in-person interviews with two external candidates who are people of color or women, or both, though the change potentially creates a loophole that could decrease the number of candidates of color interviewing for top jobs.

The league also announced the creation of a six-person diversity advisory committee to examine its diversity, equity and inclusion policies. Its members include Rick Smith, the former Houston Texans general manager, and Peter Harvey, the former New Jersey attorney general who advised the league on its 2017 investigation into domestic violence allegations against Dallas Cowboys running back Ezekiel Elliott.