Cleveland Browns star Myles Garrett has been banned indefinitely without pay after his violent assault on Pitssburgh Steelers quarterback Mason Rudolph.

Garrett clashed with Rudolph during the final play of Thursday's clash and proceeded to rip off his rival's helmet before hitting him over the head with it.

The defensive end released a statement on Friday apologising for his behaviour and taking responsiblity for his actions after being widely condemned by critics including his own team-mates.

'Last night, I made a terrible mistake,' he said in a post on Cleveland Browns' Twitter account. I lost my cool and what I did was selfish and unacceptable. I know that we are all responsible for our actions and I can only prove my true character through my actions moving forward.

Myles Garrett attempts to strike Pittsburgh Steelers quarterback Mason Rudolph on Thursday

The Cleveland Browns defensive end connects with his opponents at the FirstEnergy Stadium

Rudolph's team-mates square up to Garrett following the incident on Thursday night

'I want to apologise to Mason Rudolph, my team-mates, our entire organisation, our fans and to the NFL. I know I have to be accountable for what happened, I learn from my mistake and I fully intend to do so.'

Commentators were aghast, with Fox head announcer Joe Buck describing the incident as 'one of the worst things I've ever seen on a professional sports field.'

Garrett was ejected after the ensuing melee, with just eight seconds left in the game and Cleveland already assured of the victory. Garrett most likely faces at a multi-game suspension by the league.

The incident started when Garrett tackled Rudolph well after the quarterback had thrown the ball.

Rudolph clearly took offense, and grabbed at Garrett's helmet. Garrett then did likewise and managed to rip off Rudolph's helmet before using it to strike the quarterback in the head.

Pittsburgh players were incensed, with center Maurkice Pouncey throwing a couple of punches at Garrett, before trying to kick him in the head after he was wrestled to the ground.

'Oh gosh. Oh my goodness,' Buck said as he watched a slow-motion replay of the incident.

Garrett and Pouncey were ejected, as was another Cleveland player, Larry Ogunjobi, who pushed Rudolph to the ground.

The attack sparked a mass brawl which involved both sets of players scrapping in the end zone

Rudolph did not appear to be seriously injured by the helmet strike.

Garrett admitted afterwards that his actions were 'foolish' when he was questioned on his ejection by reporters.

'What I did was foolish, and I shouldn't allow myself to slip like that,' Garrett said. 'That's out of character, but a situation like that where it's an emotional game, and I allowed myself to fall into those emotions with what happened.'

His coach, Freddie Kitchens, described his actions as 'embarrassing', while Browns quarterback Baker Mayfield did not defend his team-mate's behavior, either.

'I didn't see why it started but it's inexcusable,' Mayfield, referring to Garrett, told Fox. 'I don't care, rivalry or not, we can't do that.

Garrett was expelled from the game and is facing a multi-game suspension from the NFL

'That's just endangering the other team. He's going to get suspended. We don't know how long and that hurts our team.'

Cleveland won the game 21-7, improving to 4-6 on the season, while the Steelers dropped to 5-5.

The teams meet again in 17 days.