James Lawton: Ireland's loner discovers the team is more important

McCarthy left with no choice but to send isolated captain home as challenge to authority threatens to destroy Republic's morale

Why would a footballer turn his back on the World Cup, and not just any footballer but one like Roy Keane, one whose need to compete is as fundamental as the one he has for his next breath?

Because – those who know him best suspect – he has weariness in his bones and in his spirit. For Keane the tournament, which is about to captivate almost every corner of the world and is for so many a huge daubing of colour in their lives, had become another job, another challenge – and perhaps one too far.

It is not so much that he has betrayed his reputation as football's ultimate warrior. It is more that he appears to have exhausted it, worn down not just himself but all those around him. He was always a contradiction: the team man who was always a fierce, brooding loner. But now he had crossed a line, at least in the Irish dressing-room. The weight of his presence, and his anger, had simply become unsupportable.

As it finally turned out, Keane's long and, we have to believe, tormented flight home, might be said to have been involuntary. But that is a nicety detached from the realities of one of the most haunting World Cup stories we have ever known. The Irish coach, Mick McCarthy, sent Keane home because in the end he had no choice. The envelope that the player refused to stop pushing might, as far as the coach was concerned, just as well have contained high explosive. It threatened to blow all of McCarthy's work to pieces.

McCarthy probably now regrets that he was talked out of his original decision to banish Keane by the player's club manager, Sir Alex Ferguson, and his adviser and friend, Michael Kennedy, because what could have looked like a sturdy stand on principle now resembles not much more than a bowing to the inevitable. Keane, whatever he did on the field in the next few weeks, was beyond redemption as a team man. He had spread too much doubt in the dressing-room and, at a World Cup, doubt between a coach and his players is poison. It strips away the authority of the man who is supposed to be in charge. It makes him vulnerable to any minor rebellion from wherever it springs.

But then McCarthy had reason enough to separate himself from that classic truth of football. If a coach is ever going to compromise his principles he needs a compelling reason, and having Keane, even a scowling, disaffected, homesick Keane, at the heart of your team surely qualifies quite uniquely in the context of the Irish team.

No player can ever have carried his team so superbly to the game's greatest tournament. Injured, agitated by the dwindling of so many certainties at Old Trafford, Keane was a surging moral force for Ireland, as he was for United. He is a far from charming footballer. There is little grace about his work. His style is a raging functionalism lifted by a killer's eye for any hint of weakness in the opposition.

He forced United into the 1999 European Cup as astonishingly as he brought Ireland to Japan, and if this week's events have stunned his homeland to its core it is not because of affection for the nation's greatest footballer but the previously unassailable conviction that he would lead – brilliantly, indefatigably – all of its football battles.

Keane's apologists, whose numbers are sharply reduced as McCarthy seeks to gather his troops together at the broken place of Keane's loss, are not without arguments. They point out that he was appalled by the holiday atmosphere of the training headquarters, unimpressed by drinking that stretched into the small hours, and that, not for the first time in his international career, an Irish practice session was something of a shambles. Why would a man of Keane's motivation, his single-mindedness in the matter of success, be obliged to tolerate such sloppiness?

Because, most basically, being a member of a team is about at least a degree of tolerance. Keane happens to be a loner who chooses not to room with team-mates. It is not unknown, but where the Irish captain oversteps the mark is in his attitude to the preservation of certain civilities – and most obviously the relationship between the coach and his players.

When Keane exploded on the practice pitch it seems that long-standing friction was coming to the surface. The goalkeepers' coach, Pat Bonner, happened to catch Keane's rage but McCarthy was not slow to pick up the implications. It was his leadership that was being challenged, his style that was questioned when a water bottle was thrown to the ground.

So soon enough the split was formalised. After Keane made veiled but damning references to the handling of the team, when, with impossibly inappropriate timing, he announced his impending retirement from international football, McCarthy was forced to act. Keane got his ticket to ride home, McCarthy got his team back.

That it is a team hugely weakened by Keane's absence almost goes without saying. It has lost so much more than its captain. It has lost its competitive heart, its belief that when Keane was on the field no opposition was too formidable, no odds too great. That was Keane's declaration when he fashioned one of the World Cup's most impressive qualifying achievements, the splitting of the powerful Portugal and Netherlands, and if he could do it against such opposition, why not Cameroon and Germany and Saudi Arabia when the big show opened in a week's time?

That particular optimism died in the rage of Keane on the practice field. Then it was clear that for Ireland at least he had had his fill of the team game. His intolerance of so much that he had come to dominate flooded out and the damage, McCarthy knew deep down, was irreparable. Some will always wonder why he didn't act then, but it is not easy to amputate your strongest limb.

Above all, Keane's departure is a sadness, and none the less because it became so inevitable. He had to go, but his every step away was an assault on the spirit of a game which can ill afford to lose at its highest level the will of the player who most hated to lose.

When the red mist descends: the troubled times of Roy Keane

1991

Arrives 30 minutes late for hotel departure on first Republic of Ireland trip, age 19, and tells a furious Jack Charlton: "I didn't ask you to wait, did I?"

1992

Arrested outside a Nottingham night-club amid rowdy scenes. Released without charge.

1993

Thrown out of another night-club in January for involvement in a brawl. In July, joins Manchester Utd from Nottingham Forest for a British record fee of £3.75m.

1995

Sent off for first time in career, for stamping on Crystal Palace's Gareth Southgate during an FA Cup semi-final replay on 12 April. Subsequent FA disrepute charge leads to £5,000 fine. Sent off twice later in the year, at Blackburn in August and against Middlesbrough (right) in October.

1996

Sent off in March during his 30th appearance for the Republic of Ireland, against Russia, in Mick McCarthy's first match as manager. In May, goes on holiday to Italy, missing McCarthy's testimonial and international training. Is later left out for six international games.

1997

Escapes punishment after being involved in a head-butting incident during a Republic of Ireland match against Romania in April in which he misses a penalty. Interviewed by police in September over claims that he threatened a neighbour during a row over his straying dogs. The same month he suffers a knee injury that keeps him out for the rest of the season.

1999

Says in January he will leave United if his new contract does not satisfy him. Sent off in April in FA Cup semi-final against Arsenal. Booked in the Champions' League semi-final against Juventus, ruling him out of historic final against Bayern Munich. Arrested in May after claims he kicked a woman in a bar, but released without charge.

2000

Sent off against Newcastle in February. Criticises Man Utd board the same month for their "stupid mistake" of saying increased ticket prices are a result of his wages. Sent off in the Charity Shield against Chelsea in August for two bookings. Criticises the lack of atmosphere at Old Trafford in November, accusing corporate spectators of being unable "to spell football, never mind understand it".

2001

Criticises the FA of Ireland over "abysmal" team facilities before a 4-0 Republic win in Cyprus in March. Criticises his United team-mates after a Champions' League quarter-final defeat by Bayern Munich in April. Sent off against Manchester City the same month. Sent off, for ninth time in career, against Newcastle in September.

2002

Criticises training facilities and Republic team-mates' attitude to World Cup preparation and is sent home.

Compiled by Nick Harris