Myles Garrett's appeal against his indefinite suspension has failed, with the NFL upholding the ban.

Cleveland Browns defensive end Garrett was suspended for at least the rest of the season by the NFL after he hit Mason Rudolph over the head with the Pittsburgh Steelers quarterback's helmet in the closing seconds of last Thursday's Week 11 encounter between the two teams.

Despite releasing a statement apologising to Rudolph, Garrett appealed against the league's decision, but will still be reduced to the role of spectator for the remainder of the 2019 campaign.

Appeals officer James Thrash upheld all discipline relating to Garrett, who reportedly claimed in his hearing that Rudolph made a racial slur against him in the build-up to their altercation.

Rudolph's agents – Younger & Associates/QB Limited – firmly denied the allegations, which surfaced in a report from ESPN.

"According to ESPN, in his appeal, Myles Garrett falsely asserted that Mason Rudolph uttered a racial slur toward him, prior to swinging a helmet at Mason's uncovered head, in a desperate attempt to mitigate his suspension," a statement released on Twitter said.

"This is a lie. This false allegation was never asserted by Garrett in the aftermath of the game, never suggested prior to the hearing, and conspicuously absent in the apology published by the Browns and adopted by Garrett.

"The malicious use of this wild and unfounded allegation is an assault on Mason's integrity which is far worse than the physical assault witnessed on Thursday.

"This is reckless and shameful. We will have no further comment."

Browns defensive tackle Larry Ogunjobi's one-game ban for his role in the incident was upheld, though he had a fine of $10,527 rescinded.

Appeals officer Derrick Brooks, who dealt with the case of Maurkice Pouncey, reduced the Steelers center's suspension from three games to two, though he upheld a $35,096 fine.