Murphy was the manager of Rockmount boys team, and in Cork schoolboy football, they were kings. The club scouts came – a contract in one hand, a dream in the other. Keane wasn’t their first choice, nor their second, not even their third. He was small, gritty rather than gifted. But when you patrol the touchline, as Murphy did, every training session, every game, you know. Better than the scouts, you just know. “Even then, at the age of 11, Roy was the leader.”

During the evening, Murphy pulled out a photograph. “See this? First trophy Roy Keane ever won in football.” Rockmount U11s, seven boys sitting, seven standing; their statuettes lined up in front of them. Keane is the smallest – but the look on his face is unremittingly hard. The statuette could have been a dead fish by his feet.

What made him like that? He came from a country once described by the businessman and former rugby player Tony O’Reilly as being dogged by an “it’ll do” mentality. “Sure, it’s not great, but it’ll do.” Keane comes from a part of Cork city where boys learnt to look after themselves in the early hours of Sunday morning: a world where you dreamt for a while, then got battered by reality. He did the drinking, the fighting. He has always loved his home city; “Irish by birth, Cork by the grace of God” is his verbal passport. Few exiles come back as often as he does, to stay at his parents’ house.

To be what he has become, he had to separate himself from so much that he was: the fry-ups, the drinking, the fights, the things that eat him inside that made him lash out. Perhaps, most of all, he had to survive being Roy Keane, the Roy Keane. Sir Alex Ferguson described him recently as Manchester United’s most influential player. How did he come to be that? Perhaps because he was the one who said “it’ll not do”.

He doesn’t easily agree to interviews. Two letters in the past 18 months produced nothing. A third letter was sent six weeks ago. You write it, post it and forget it. A week later, the day before his 35th birthday, my telephone rang. “This is Roy Keane. I got your letter, I don’t mind having a chat. Can you get to Manchester tomorrow by 11 o’clock?”

There had only ever been one face-to-face interview between us, four years before. The first time, he had shown up 15 minutes before the appointed time. It made me think of poor Mark Bosnich, the Australian goalkeeper who turned up late on his first morning at Manchester United’s training ground. “What do you mean, you got lost?” Keane snarled. Back then you could get past security but not past the team’s guard dog. Now he walks into the Marriott Hotel near Manchester airport at a minute past 11. It is hard to be sure it is him, but once he is through the revolving door he puts his right hand to his face, instinctively shielding himself from the outside world. It’s a dead giveaway.

Not many adults have this shyness.

Something Martina Navratilova once said came to mind. Asked why she won nine singles championships at Wimbledon, Navratilova said it was because every time she walked on Centre Court, she felt like a little Czechoslovak girl playing people better and more advantaged than her. Keane came with that same mentality: “Roy, they think they’re better than you.”

We sit in a room at the back of the hotel. There is coffee and water. He chooses water and though three months have passed since he last kicked a football, his pencil-thin physique remains untouched by retirement. He talks about the way he changed his diet. “When I changed my diet, I went from the player with the highest body fat to the one with the lowest body fat. Typical me, has to be all or nothing.”

He tells about a recent visit to Ireland and an invitation to speak to the Cork hurling team: how he sensed a bond among these amateur sportsmen that you don’t get in professional football. He spoke of the togetherness; a natural occurrence, he thought, among men who had played together in underage teams and grown up together.

When he watches them play, he can see that camaraderie and it pleases him. I ask: “Were they not intimidated?” He pauses briefly: “Intrigued. Always trying to get inside my head.” So, then, the Cork hurlers are no different from the rest of us.

What went on inside his head when Sir Alex Ferguson let it be known he was no longer wanted at Manchester United? Twelve years of his life at the club, his wracked body became an offering, his soul became the team’s soul. Then, at the end of one bad week, it was over. The exit was quietly played out. Not much was said. “I just knew it was time to go. Everybody knew. Sixth sense, I suppose.”