From superhero to Roy of the Ravers

What we have seen in Roy Keane this past week needs no explanation from the psychiatrist's couch. His actions are entirely consistent with the man we know. Keane has a short fuse. He has been sent off nine times in his career. This was the 10th.

But a number of myths disappeared with Keane into the plush leather seats of the executive-class jet sent to bring home the prodigal son. No longer will anyone be able to talk in hushed tones of Keane, the ultimate professional. What sort of professional abandons his team-mates on the eve of a World Cup? What sort of captain leads so far from the front, he is back at home before the first ball has been kicked?

The most poignant image of the whole sad drama could be conjured from the sound of the Irish squad singing their pleasure at Keane's departure on the team bus. The case for the prosecution needed no more persuasive piece of evidence. Though every one of the Irish players admires Keane the footballer, knows deep down that without him they would probably be watching the World Cup on television, their damning verdict was delivered on his current qualities as a man. The Irish team are nothing if they are not united in purpose, and the clear message was that Keane's brooding presence was destroying the sense of community. McCarthy saw the problem two years ago and has been searching for a solution ever since.

Yet you have to ask a number of questions not just about McCarthy's inability to harness such a turbulent nature to the common cause, but about Keane's descent into tortured seclusion. Not that long ago, at the height of the speculation surrounding Sir Alex Ferguson's succession at Old Trafford, Keane emerged for a brief spell as a sharp and eloquent spokesman for his team. He broke his embargo on interviews, wrote a provocative column for a national daily and seemed on the verge of embracing a welcome maturity. He tentatively put forward his own credentials as a manager. But with Ferguson's volte face and a troublesome knee injury came renewed torment and, encouraged by a manager who has always regarded his tempestuous behaviour as the epitome of the United spirit, a return to the days of glorious isolation. Barely a day went by in the press room without Ferguson lauding his captain fantastic, while, on the field, Keane's tongue-lashings seemed increasingly desperate and ineffective. Juan Veron, for one, was distinctly unimpressed.

Reports that United offered to send out the private jet to collect their troubled star simply reflects the problem, not just a potential insult to the Irish Football Association, the ultimate triumph of affluent club over impoverished country, but a gesture designed to pitch Keane into a darker seclusion. Suddenly, he is no longer a footballer, but a flouncing movie idol who has been denied the biggest dressing-room and needs an ego-massage from his entourage. Come home, Roy, stop playing with those rough folk from across the water. Never mind that the majority of Ireland thought a long flight back in economy class might be the more bracing punishment.

The move bears the hallmark of the United manager, who will be pleased to have his captain back in the fold. The bond between Keane and Ferguson has been at the heart of United's triumph. It is an extraordinary relationship, built on the unspoken acknowledgement that Keane is the sort of player Ferguson once aspired to be and that Ferguson is the sort of leader Keane aspires to be. The mutual recognition stems from a shared background and a unshakeable belief in the virtues of loyalty and industry. Keane is the only player allowed to voice dissent from the heart of the United dressing-room. Accusations against, at one time or another, players, supporters and directors have been afforded a hearty "hear, hear" by the majority, who relish a spat inside football's royal house, but Keane's sense of omnipotence has proved to be explosively at odds with the robust democracy on which the Irish team have traditionally thrived. In sending home his most influential player, McCarthy was only reasserting what he instinctively knew to be the ultimate strength of his nation's sporting character.

Yet McCarthy's man management should be no less open to scrutiny than Keane's temper. McCarthy is patently a decent man, the son of a coal-miner who made the most of his strengths as a footballer and who has made a decent fist of succeeding Jack Charlton in the role of miracle-achiever at the Irish FA. Knocking Holland out of the World Cup qualifying group matched any of his predecessor's more glamorous feats. But McCarthy has paid the penalty for over-indulging his one world-class player and stands accused of deliberately orchestrating Keane's farewell.

The clear-the-air meeting which descended into an asterisk-filled personal attack on the coach – and team-mates – could have been conducted in a less public forum, outside the earshot of the rest of the squad. It is the classic coach's dilemma. How many exceptions do you make for an exceptional player?

Keane had used up a number of his lives by consistently flaunting McCarthy's authority over the past two years. But McCarthy must have known that singing songs and staying up late in a Pacific island with limited facilities was not his captain's idea of a World Cup preparation. Perhaps Keane could have been allowed to skip the singing and simply arrive for the period of real acclimatisation in Japan. If the timing of Keane's defection has been the subject of the most savage criticism, the finger can equally be pointed at McCarthy for postponing the inevitable challenge to his captain until such a critical moment. The feud has been smouldering for a year or two now.

It remains to be seen whether the relief of Keane's exit stretches deep into the opening game on Saturday against a side as strong as Cameroon. The Irish will do well to qualify now.

Keane's own peace of mind is an equal cause for concern. Those who know him well say that Keane can be charming and generous company. Even some of his stronger critics in the Irish press admit there is another Roy Keane, the relaxed and unrecognisable character who appeared before them late into the night after United's victory in the European Cup final, chatting amiably about life and ambition. Those appearances became rare in recent months as United's failures piled up and Keane sat helplessly on the sidelines.

Speaking to an old pro last week about Keane brought some glimmer of understanding. "You know, as I got older, I became less tolerant," he said. "I'd eff and blind about a bad pass in training or I'd clatter into someone. The others would say 'Why did you do that?' and the funny thing was, I didn't know why. You just start to realise that time is no longer on your side." Keane has more time than he bargained for now, but reality will dawn sooner or later. For all his many achievements, he will forever be remembered as the man who walked out on a World Cup.