Mason Rudolph said Myles Garrett's claim the Pittsburgh Steelers quarterback racially abused him prior to their on-field brawl in November is a "bold-faced lie" and "1,000 per cent false".
Garrett was suspended indefinitely by the NFL after he ripped off Rudolph's helmet and hit him over the head with it in the closing stages of the Cleveland Browns' Week 10 victory over the Steelers.
Although Garrett initially apologised for his actions, he subsequently accused Rudolph of using a racial slur, a claim that was vehemently denied by the Steelers signal-caller at the time.
Following an investigation, an NFL spokesperson said the league found "no evidence" to support Garrett's allegation.
After being reinstated by the Browns this week, Garrett again said Rudolph racially abused him, telling ESPN: "He called me the N-word. He called me a 'stupid N-word'."
Responding to a clip of the interview on Twitter, Rudolph said: "1,000 per cent false. Bold-faced lie. I did not, have not, and would not utter a racial slur.
"This is a disgusting and reckless attempt to assassinate my character."
Rudolph's attorney and agent Timothy M. Younger suggested legal action could be taken against Garrett.
A statement posted by Younger read: "We waited to hear the entire interview. Garrett, after originally apologising to Mason Rudolph, has made the ill-advised choice of publishing the belated and false accusation that Mr. Rudolph uttered a racial slur on the night in question.
"Not that Mr. Garrett claims that Mr. Rudolph uttered the slur simultaneously with being taken down, and before Mr. Garrett committed a battery by striking Mr. Rudolph on the head with a 6 lb helmet.
"His claim is ludicrous. The obviously was not the first time Mr. Rudolph had been sacked by an African American player. Mr. Garrett maliciously uses this false allegation to cox sympathy, hoping to be excused for what clearly is inexcusable behaviour.
"Despite other players and the referee being in the immediate vicinity, there are zero corroborating witnesses – as confirmed by the NFL.
"Although Mr. Rudolph had hoped to move forward, it is Mr. Garrett who has decided to utter this defamatory statement – in California. He is now exposed to legal liability."
Steelers head coach Mike Tomlin said: "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.
"I interacted with a lot of people in the Cleveland Browns organisation – players and coaches. If Mason said what Myles claimed, it would have come out during the many interactions I had with those in the Browns organisation.
"In my conversations, I had a lot of expressions of sorrow for what transpired. I received no indication of anything racial or anything of that nature in those interactions."