HE WAS Manchester United's midfield enforcer for more than a decade, but the hardest part of Roy Keane is his tongue, according to his former manager Alex Ferguson.
Ferguson admits that Keane would become "frightening" when he was angry, with his eyes narrowing to "black beads".
"It was frightening to watch. And I'm from Glasgow," added the club manager of 26 years.
In his new autobiography which will be published tomorrow, Ferguson lifts the lid on his fractured relationship with the Ireland international, which ended in Keane's sudden departure from the club in 2005.
Ferguson devotes an entire chapter to Roy Keane in his new book 'My Autobiography' and profiles the Corkman who was himself part of the Manchester United story for 12 years.
"He has the most savage tongue you can imagine. He can debilitate the most confident person in the world in seconds with that tongue," writes Ferguson.
"What I noticed about him that day as I was arguing with him was that his eyes started to narrow, almost to wee black beads. It was frightening to watch. And I'm from Glasgow."
Responding to his former manager's book, Keane said that he wouldn't lose any sleep over the criticism of him and other former Manchester United players.
He said he doesn't "think (Ferguson) knows the meaning of the word loyalty".
"I just don't think a manager needs to do that, I'm not sure how many books he's written now," he said on ITV last night.
"But he has to draw the line eventually to say, listen, these players have all been top servants to Man United.
"And a lot of these players helped the manager win lots of trophies. So you can imagine if we'd never won a trophy what he would have said.
"You know, we brought success to the club, we gave it everything we had when we were there so, as I said, its just part of modern life that people like to do books and criticise their ex-players."
Ferguson at first compliments Keane as "an immense driving force" over many years as the team leader.
"Roy took a lot of the onus off me in making sure the dressing room was operating at a high level of motivation," Ferguson writes.
However, he says that by the time Keane left United in November 2005, their relationship had collapsed.
He says that Keane had difficulty coming to terms with the fact that age and injuries had slowed him down and that he could no longer chase the ball all over the park.
"He thought he was Peter Pan," Ferguson writes.
Ferguson says that they told him to stay in the central midfield area but Keane had difficulty accepting a more limited role.
"I think he could see the truth of what we were saying, but to surrender to it was too threatening to his pride," Ferguson writes.
He believes this was the context for the confrontation that ended with him leaving the club.
Ferguson goes into detail about two rows that brought matters to a head.
The first was the pre-season training trip to Vale do Lobo in the Algarve before the 2005-06 season.
Assistant manager Carlos Queiroz had set it up but Keane wasn't happy because some of the rooms in the houses did not have air conditioning. He wanted to stay in the more upmarket development nearby called Quinta do Lago.
According to Ferguson, Keane became "reclusive" during the trip and had a long list of complaints. When they got back to Manchester, Ferguson said that he and Keane had "a real set-to".
Then came the second blow-up, which was over an MUTV interview in which Keane let rip at the players in the team who he thought were not pulling their weight.
When Ferguson was told about it, he stopped the broadcast and said he would review the tape the next day.
"Jesus. It was unbelievable. He slaughtered everyone," Ferguson writes.
Later at a meeting with Keane, he told him the interview was "a disgrace, a joke. Criticising your team-mates. And you wanted that to go out."
Keane argued back that the tape should be shown to a meeting of the players and let them decide.
Ferguson agreed, and when the showing was over, Keane asked the players for their views.
According to Ferguson, goalkeeper Edwin van der Sar told Keane he was out of line and Keane attacked him. Then striker Ruud Van Nistelrooy spoke up to support Van der Sar, and Keane attacked him as well, before rounding on Carlos Queiroz.
"But he saved the best for me," Ferguson writes.
He says that Keane accused him of bringing his "private life into the club" in a row with Coolmore Stud boss John Magnier over ownership of champion racehorse Rock Of Gibraltar.
At that point, Ferguson writes, players started walking out.
"After Roy had left, Carlos saw I was quite upset," Ferguson writes.
Queiroz said he had never seen anything like it in his life, that it was the worst spectacle in the life of a professional football club.
"He needs to go, Carlos," Ferguson said. "One hundred per cent," Queiroz replied. "Get rid of him."
My Autobiography by Alex Ferguson is published in hardback tomorrow by Hodder & Stoughton at €33.35
by John Spain Books Editor