At his best Michael Donnellan has everything: pace, accurate kicking off either foot and a supremely competitive spirit, cajoling and encouraging his team-mates. Like great sportsmen, he rises to the occasion and has nearly always delivered his best on big days in Croke Park, like tomorrow's All-Ireland final against Kerry.

If he was almost born to these accomplishments - his father and grandfather won All-Irelands before him - his short career has also been shrouded in enough controversy to last a veteran. This is part of the central paradoxes in Donnellan's personality.

On the field he is well placed to become one of the game's great players. Many who have followed his football career can't find a single fault in his technique. Yet his game is totally dependent on his motivation. Unless the focus locks on football, he is prone to anonymous displays such as last year's Connacht final.

Off the field he is the epitome of what a young sports celebrity should be. Although he politely refuses interviews with print journalists, he is open and courteous about it. At press nights he turns up, talks to broadcast media and signs autographs for children. This pleasant personality, combined with his beatific expression, makes him an obvious target when the endorsement business is up and running within the GAA. Yet there is a petulant side, a tendency to store grievance which occasionally erupts into stubbornly unrepented retaliation.

He was born 23 years ago. Michael's father, John (later a Fine Gael TD and Minister for State), captained the first of Galway's three-in-a-row winning sides in 1964. The same day Mick Donnellan, John's father, died at Croke Park. He too had won an All-Ireland and he held the Dail seat John was to keep in the family until 1989 when he retired.

Although he performed legendary feats at St Jarlath's, the famed football school in Tuam, it was even earlier that Michael Donnellan caught the attention. Ollie Turner, a journalist with Galway Bay FM, played on under-age teams with the young Donnellan.

"I'd say he first shone at national school level. Ballinlass is a very small school in the Dunmore parish and in the final of the Murphy trophies, he played midfield and scored 2-7. That really brought him to prominence."

From then on, progress was relentless. At Jarlath's he played two Hogan Cup finals, losing the first to St Colman's Newry and Diarmuid Marsden but was one of the best players on the pitch. A year later against a hotly fancied St Patrick's Maghera, Jarlath's were underdogs but Donnellan was to the fore as the odds were overturned. Fr Ollie Hughes, president of St Jarlath's, picks the 1994 final as his most enduring memory of the player.

"He was absolutely outstanding. We brought him out to midfield and he gave an exhibition. One thing about him is that he's made for the big stage."

"There was," according to John Tobin of Tuam rivals St Patrick's CBS and a former Galway manager, "very little you could do about him. He was exceptional at juvenile level and up. He could beat a team on his own and it showed all the way through."

Under-age inter-county action came and went and with it, the first experience of the big stage on All-Ireland day in the 1994 minor final.

The senior call-up came in 1997, under Val Daly's management, when Mayo won in Tuam for the first time in 46 years. But Donnellan's pace caught the eye, particularly in a rousing first-half period before the more experienced Mayo moved on towards a second successive All-Ireland final.

Nearly everyone who comments on Donnellan points out that he is a big-game player. So it proved in 1998. With John O'Mahony in charge of the team, a tricky Connacht campaign was negotiated. Donnellan played his part but it was his Croke Park performances which really stood out and earned him all the end-of-year plaudits.

The cause of much ambivalence towards him is what happened next. Galway - like a long line of All-Ireland champions before them - didn't cope well with the pressures of success. As the long-awaited triumph unlocked coffers, resentments surfaced over who received what and disaffection set in.

Worse was to come. After an unpleasant county championship match between Donnellan's Dunmore McHales club and All-Ireland champions Corofin (between whom there have been - euphemistically speaking - poor relations), referee Tommy Gavin was attacked and knocked to the ground. Donnellan was widely reported to have been involved but in a denouement straight from John B Keane, an investigation discovered that no one in a crowd of 4,000 had seen what happened.

The media was neatly positioned as the real source of the problem and the dismal jurisprudence of "trial by media" was conjured up in defence of anyone who might be involved - except of course the referee.

For whatever reason, Galway's karma appeared bad that championship. The display in the second half of the Connacht final was dreadful and Mayo relieved the champions of at least one of their titles. In the aftermath Donnellan went to the US but returned in time for selection on the International Rules panel to travel to Australia.

"His talents for the international game are obvious," says John Tobin, coaching adversary from schooldays and one of the backroom team in Australia. "Speed and stamina. He got home quite late from America but picked it up again immediately. He's fierce determined. If he wants to do something, he'll jump stone walls to do it."

Further controversy followed when Donnellan decided to play soccer with National League side Galway United. Although his soccer experience had been largely confined to Dunmore Town, he proved a success in one respect at least. His presence attracted the curious and helped the home gates. As a player his stamina and pace couldn't quite hide his lack of technique but the sojourn was credited with one positive effect.

It got him out of the GAA world and in the eyes of some, allowed him some space after the controversies of the previous months. Whatever the motivation for the break, he returned in time to join the county panel for what has turned out to be another memorable season.

In the absence of Galway's play-maker Jarlath Fallon, Donnellan has assumed the added responsibility in impressive fashion. The bigger the challenge, the more likely he is to respond. Fr Hughes disagrees that his former pupil is temperamental but says he has the edginess of a thoroughbred.

Which of course is just what he is.