Roy Keane reveals contempt for Sir Alex Ferguson and hatred of Arsenal in ITV documentary

“Without a doubt Brian Clough,” he replies unhesitatingly. "Not Alex" asks interviewer Gabriel Clarke. “You asked the question and I answered it.”

Keane is in sparkling and candid form in a documentary that reunites him with his former midfield adversary, Arsenal’s Patrick Vieira – a meeting that took two years to engineer.

He appears to relish the opportunity to respond to Fergie’s criticisms of him in his recent book. “The manager has accused me of trying to manage Manchester United behind his back. What I was trying to do was manage the dressing room. Just because Alex Ferguson says it doesn’t mean it’s the truth. I never thought I was more important than the manager.”

Keane even turns comments made by Fergie in praise of his commitment against his former boss. “Stuff like that insults me. I actually get offended when people throw quotes like that at me as if I am supposed to be honoured by it. What am I supposed to do? That was my job. It’s like praising the postman for delivering the mail.”

Keane describes the moment in 2005 when he left the club: “I had lost respect for him (Ferguson) and he had lost respect for me. He thanked me for my eleven and a half years service and I had to tell him it was twelve and a half.

“I knew it was business. I got my boots and drove back. I was upset. Of course I was upset. I did shed some tears…for about two minutes. I could have played for United for another couple of years.”

Keane says his relationship with Ferguson is “non-existent”, and reveals that now David Moyes is in charge he has returned to Old Trafford to watch games with his son.

He also offers an honest, if controversial, view of his own approach to football. He admits, quite unapologetically, that he set out to hurt players. “That was my job and players went out to hurt me. But never to injure players. But I did go out to hurt people because that was my job.” Only Keane can answer for the subtlety of the distinction.

In the documentary, Keane & Vieira – Best of Enemies, he shares stories and memories with the former Arsenal midfielder. Keane speaks of his “hatred” for Arsenal. “Hatred was the word, because they were big rivals. I don’t remember liking anyone at Arsenal. I knew I had to be at my angriest to be my best. Every time you played you thought there was going to be fireworks.”

Together the two combative midfielders picked up a total of 21 red cards – 11 for Keane 10 for Vieira – during their Premier League careers but the on-field animosity is replaced by warmth and respect in the studio. They even choose their own favourite United and Arsenal teams – no place for Gary Neville, Ryan Giggs or Paul Scholes in Keane’s fantasy eleven.

For fans of football, regardless of club loyalty, it’s an absorbing watch. Two of the biggest characters to have both graced and, at times, despoiled, the game trading punches and memories in an utterly compelling way. Don’t miss it.

Keane and Vieira – Best of Enemies is on ITV4 at 10pm on Tuesday 10 December