From Playing at Home, John Aizlewood's otherwise splendid book about watching a season of English football, one line clanks around in the memory. "Thus," says Aizlewood, describing an afternoon spent at Elland Road watching Leeds play Manchester United, "Roy Keane, so thick that even other footballers must notice, will get himself carried off and booked at the same time." How wrong can one man be. If there is a more complex or interesting character playing soccer in Britain today, he has yet to reveal himself. Keane, at the height of his extraordinary powers, is a singular man and there is a good case for making his press conferences ticket-only affairs.

Watching as he has metamorphosed into the man and the player he is has been instructive. The footie writers' sketches of Keane draw down Psycho and Rambo as reference points for his supposedly incoherent rage, but there is a poignant touch of The Truman Show about the way Keane has identified a world of normality beyond the goldfish-bowl life of Old Trafford. He guards his privacy zealously and he has renounced the bland soccer-speak of his brethern. "Fiftieth cap, Roy," we asked him the other morning, taking him through the warm-up with an easy one, "what does it mean to you?"

We're ready to scribble the telegraph version of the answer: Over moon. Landmark. Never Thought It. Playing For My Country. Highest Honour. Many More. Fingers Crossed. Up To Gaffer!

Instead, Keane says levelly: "Absolutely nothing. It doesn't mean a thing." Even in the press room, where we've heard it all before in 19 different languages, there is a nervous gasp. So Keane has to preempt the hold-the-front-page calls.

"I'm not saying that I don't love playing for Ireland. I'm just saying the 50th cap isn't different to the rest. It's a game. Fifty caps?" And he grins. "Maybe without injuries and `communications problems', we'd have been past that a while ago, there'd be a little bit more. It means nothing, 50 caps."

So there'll be no cake with candles tomorrow night. Keane has come here to win and to move on. In the past couple of years, since he became aware of his own footballing mortality, he has brought a renewed vigour to his efforts with the Irish team. The World Cup of 1994, when he was this country's best player, is a long way away. He is impatient for another one.

"There's only me, Quinny, Stan and Kells who played then. We've had some decent performances over the years, but things like the Macedonia game, you know when we could have qualified for a major tournament . . . We have to win this kind of match if we want to try and get to Japan. Macedonia. The name doesn't send a shudder down Keane's spine. He's left it in the past.

"I'd like to think the team has moved on a little bit from a few years ago. The squad is stronger . . . Over here we're expected to win the match. So what's happened in the past, we've got to forget about it."

So. Any thoughts of being captain of Ireland at a World Cup? "It's not about me leading anything, it's about the country qualifying. It's not about me. I'd enjoy it, yeah. I enjoyed the last World Cup. It would be nice just to be there again. Watching on the telly is very frustrating. I don't think we'll ever be capable of winning the World Cup. First and foremost it would be nice to qualify." He's fidgety to be off. We fish for a prediction, something emphatic about the outcome.

"Teams at all levels struggle when the onus is on them to go out and get a result," he says. "It's a different scenario. It's up to us to put the pressure on and most importantly to score a goal. If you want to qualify, if you want to win trophies, you have to go and win this kind of game."

And he glances to the door as a preliminary to getting up and heading for it. This week's thoughts to the nation dispensed.

"Roy," this journalist said to one of the Irish backroom staff this week, "he can be a bit moody, can he?" And the look was one of surprise. "No. He's private. That's all. Intensely. There's not a bit of Big Time Charlie in him."

And that's it. If he stands out among other professionals, it is the totality of his commitment, the intensity in everything he does. On the training ground, his lean frame tells the story of his self-denial in the latter half of his career. You couldn't slice a sliver of fat off him with a scalpel. Then there is the face, which seems cut from a movie about hard times in the French Foreign Legion, stubble jawed, deep-set eyes and the mouth which expresses anger or joy with the same efficiency. On a bad day, you'd run from one of those serial-killer smiles.

In Nicosia tomorrow evening, it's the first thing the slightly-awed Cypriots will notice, just when there is nowhere to run and nowhere to hide.