As one of the most combustible players of his generation, Roy Keane often appeared to be driven by fury, but for the good of his health, the Irishman has made an effort to maintain his composure since his move into the dugout. “It would probably have put me in an early grave,” the Sunderland manager said yesterday. Referees should realise how lucky they are.

After 13 months in his new position, Keane has stayed true to his word, even if, on occasion, he has been required to bite his tongue. “It’s very hard to stay quiet on the touchline, believe me,” he said. “But I made the decision that I would not be ranting and raving on the sidelines. If I’m going to lose my rag, I want to do it in the privacy of our dressing-room.

“Of course I’ve got to get my points across, but I see other managers ranting and think that’s not a road I want to go down. Not yet. I don’t find it difficult to appear detached. I’m not trying to be someone I’m not. If something needs to be said or I’m disappointed with a decision, then you make it clear, but I’m comfortable with what I am doing.

“I’m not one for jumping up and trying to get opposition players booked. You see enough of that around, appealing against every decision. I’m not going to lose my rag about a throw-in on the halfway line. I see other managers and think, ‘If you’ re going to lose it, at least do it for a major decision like a penalty or a sending-off.’ In a sense I think it’s a waste of time.”

The health issue is one he takes seriously. “There’s a logic to it,” Keane said. “Towards the end of my playing career I tried not to lose my rag every two minutes. It saps you of your energy and then maybe you can’t get a clear thought on the game. I try to keep calm. I don’t remember any silly bookings or sendings-off in my last season or two. Maybe it just comes with maturity as you get older.

“In the same way, if I’m ranting and raving on the sidelines then maybe I’ll lose focus on the game and tend to focus on decisions that have gone against us or on the referee. With some managers, you don’t know if they are losing it or it’s just a habit they are in now. Some managers are losing it all the time, but I think the players like it when they look over and see us in control.

“We can make our points in the dressing-room and during the week in training and I believe you’ve got to have that ultimate trust in the players and say to them, ‘Listen, we’ve done the work, trust each other and go out and do it.’ To be honest, when you’re out on the pitch - and this is just my experience – I never took too much notice of what the manager was saying or doing anyway.”

Yet such steely resolve not to be swept away by emotion might surprise some people; the image of Keane in his Manchester United strip berating officials, opponents and even teammates is so recognisable. It poses the question of whether those closest to him are intrigued by his transformation. “I have not got a clue and it doesn’t interest me what they think,” he said.

Keane’s team play Blackburn Rovers at the Stadium of Light today. Blackburn are managed by Mark Hughes, his former Old Trafford colleague, who is far more complex than his stereotype. As well as considering whether to appoint a director of football, Keane is willing to introduce his Sunderland squad to psychology. “We’re looking at things like that,” he said. “Nobody is going to be here day to day, but I wouldn’t dismiss it. You’ve got to be open-minded.”