Former Arizona Cardinals head coach Steve Wilks and longtime defensive assistant Ray Horton have joined Brian Flores as plaintiffs in the former Miami Dolphins coach’s discrimination lawsuit against the NFL.

In an amended complaint filed Thursday and obtained by USA TODAY Sports, Horton alleges the Tennessee Titans interviewed him for their head coaching vacancy in 2016 despite having already promised the job to interim head coach Mike Mularkey.

Wilks, meanwhile, claims he was “unfairly and discriminatorily fired” by the Cardinals in 2018 after just one season at the helm.

“When Coach Flores filed this action, I knew I owed it to myself, and to all Black NFL coaches and aspiring coaches, to stand with him,” Wilks, who is now the defensive pass game coordinator and secondary coach for the Carolina Panthers, said in a statement. “This lawsuit has shed further important light on a problem that we all know exists, but that too few are willing to confront.”

The amended complaint also includes new allegations that the Houston Texans and Dolphins have retaliated against Flores in the two-plus months since he first filed suit against the league.

The Cardinals, Texans and Titans generally denied the key claims made against them in a series of statements Thursday. A Dolphins spokesperson did not immediately reply to a message from USA TODAY Sports.

The NFL declined to comment through spokesperson Brian McCarthy. The league has previously pledged to defend itself against the claims in Flores’ suit, saying they are “without merit.”

The addition of two plaintiffs – and specific allegations of discrimination against three more teams – marks a significant expansion of Flores’ original lawsuit, which attorneys Douglas Wigdor and John Elefterakis filed in federal court in New York on Feb. 1.

Flores, who was fired by the Dolphins earlier this year, has alleged that the NFL and its teams engage in “systemic racial discrimination” in their hiring and firing of minority coaches.