Gabriel Heinze has given an interview on Argentinian television claiming that Roy Keane once knocked him unconscious in the dressing room on the back of a defeat.

We lost a game and I went in the dressing room first and Roy Keane was second. I liked to go first after the game; I didn’t want to speak to anyone as we lost.

I didn’t understand English, just the bad words. I heard my name and “fuck off” by Roy Keane, the best player. I knew that was bad so I stood up to him, this idol of Manchester, this great guy who everyone loved and replied “fuck off, you”. I don’t remember what happened next.

Heinze was asked: “Did he punch you? Knock you out?”

Heinze replied: “Yes. Yes.”

There was clearly no love lost between the two players though. In his autobiography, Keane reflected on a spat the two players had in training.

He was a nasty fucker – nasty in training. We were playing Spurs at home the next day, and we’d always have light training the day before a home game. But it got a bit nasty and it ended up with myself and Gabby having a few tackles on each other.

He kneed me on the side of my leg and, being the hero that I am, I kept my mouth shut. I didn’t want to go in for treatment, but I was in agony.

In 2007, Heinze was replaced by Patrice Evra in the starting XI. The Argentinian then tried to force through a move to Liverpool but the club didn’t allow it.

Four years later, Heinze revealed how much he regretted the way he behaved at United.

“I don’t have many regrets from my career as a footballer, but that episode with Ferguson [has] to be one of them,” he said. “I’m impulsive and strong-willed and this has got me into trouble at times, which was the case when I left United. I spent three years in Manchester and had some great moments and I regret it [leaving the club] a lot. There are a lot of things I regret from the last months but I am a strong personality, Sir Alex is a strong personality. I took the decision and, looking back, I regret it because it meant leaving a great club and their supporters. I was aware of the rivalry [with Liverpool], I knew the risk of going from Manchester to Liverpool and what it means. I hope it doesn’t tarnish the way they [the supporters] see me and they will remember the three years I had in the team.”