Anyone who has ever suspected Roy Keane's hard man routine may have all been just an act to psyche out the opposition or scare anyone who dares sit in a box at Old Trafford eating seafood, think again.
Ex-Man United defender Gabriel Heinze, the Argentine who signed for the club in 2004 and was named their player of the season in 04/05, has described a bust up with the Irishman in which literally no punch was pulled.
Talking to Argentine television Heinze, who now manages Argentinos Juniors, told this story.
"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 'f*** 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: 'F*** off, you'. I don't remember what happened next."
Heinze was then asked if Keane knocked him out, and replied: "Yes."
Bloody hell, Roy.
Heinze, fans of the club will remember, was no dainty quasi-winger either: this was back in the days when defenders still defended, and before he lost his place to Patrice Evra and went to Real Madrid the left-back was a beast.
"He was a nasty f***** – nasty in training," Keane said of Heinze in his autobiography, "but I liked him".
Leaving us naturally to wondering: what the hell was it like playing with Roy Keane when he didn't like you?