Pittsburgh Steelers quarterback Mason Rudolph lashed out at Myles Garrett on Saturday over an allegation of racism by the Cleveland Browns defensive player.
Garrett was reinstated by the NFL on Wednesday after being hit with an indefinite suspension for attacking Rudolph with a helmet during a stormy clash on November 15.
Garrett, who missed the final six games of the NFL season following his ban, later claimed he had reacted after Rudolph used a racial slur against him.
Rudolph has always denied the claim of racism and an NFL investigation found no evidence to support Garrett's allegation.
However Garrett on Thursday reiterated the claim in an interview with ESPN after his suspension was lifted.
"He called me the N-word," Garrett told ESPN of his fracas with Rudolph. "He called me a 'stupid N-word.'"
Rudolph reacted angrily in a statement on Twitter on Saturday, describing Garrett's allegation as "1000% false."
"Bold-Faced Lie," Rudolph wrote. "I did not, have not, and would not utter a racial-slur.
"This is a disgusting and reckless attempt to assassinate my character."
Rudolph received immediate backing from Steelers coach Mike Tomlin.
In a statement issued on Saturday, Tomlin, one of only three African-American head coaches in the NFL, said he was not aware of any racist language being used.
"I support Mason Rudolph not only because I know him, but also because I was on that field immediately following the altercation with Myles Garrett, and subsequently after the game," Tomlin said.
"If Mason said what Myles claimed, it would have come out during the many interactions I had with those in the Browns' organization.
"I received no indication of anything racial or anything of that nature in those interactions."