All-Ireland SFC Quarter-finals: It might be said that Jason Sherlock has rolled back the years and is having a season redolent of the happy and slightly insane breakthrough year of 1995. But that could not be more wrong. Nine long years ago, natural appeal, magical summer days and a successful Dublin championship season concocted the phenomenon of Jayo, a northside teenager who became the most recognisable face in the country.

Sherlock possessed a rare and unforced kinetic energy that lit the predictable suburban evenings in ways the streetlights never could. Those rays masked the fact that Dublin's last All-Ireland win was claimed more in relief than in jubilation by a tiring team that had played its best football in the luckless preceding years.

In a way, Dublin football has been transformed utterly since that benchmark season whose 10th birthday stands like an indictment of subsequent teams. And in a way, the city game has been caught in stasis, recovering from a fallout left by the retirement of several players, the criminal treatment meted out to Mickey Whelan and the cold realisation that that 1995 victory was not a beginning but an end. Irish society and the GAA and Gaelic football have changed so comprehensively since then that there is something retrospective about the sight of Sherlock, still a lean and boyish sprite, wearing the Dublin shirt as if impervious to time. It is hard to believe he has been around a decade, but perhaps less so that he remains a chief source of optimism for followers of the Blues.

When Sherlock struck his 1-4 against Roscommon a fortnight ago, Tom Carr might have allowed himself a wry smile. When he managed Dublin, Carr had absolute faith in Sherlock. The breathing space he allowed Sherlock during a time when he was exploring ongoing possibilities in the soccer world (a trial with the US franchise New England Revolution caused a stir) was invaluable for a player whose movements have never ceased to provoke strong public interest. Carr helped Sherlock flourish and his Roscommon team paid the price for that in Croke Park.

"We had singled him out as a threat; of course we did," said Carr. "Maybe we erred in the build-up to the goal, but once Jason got into open ground, I knew he would finish. He has always been a great finisher. As for the points he got, he has had that capacity for a number of years now.

"I suppose when I came in as Dublin manager, everybody had an opinion about Jason Sherlock and among those was the feeling that he was not good enough. Those were patently incorrect because he brings so much to a team. But one area we all recognised that he could improve on was his kicking.

"The thing about Jason is that if you tell him something, he is eager to work on it straight away. And he spent a lot of time just kicking under the supervision of Richie Crean."

Crean remembers those sessions. Forwards like Sherlock, Jim Gavin and Wayne McCarthy would spend half an hour after practice kicking left foot, right foot, both sides of the goalmouth.

"Then they would take a couple of footballs with them to work on their own as well," says Crean. "Much of the improvement that Jason underwent was down to his own effort. I don't know how many hours he put in, but it was a lot.

"One of the things often overlooked about Jason is that he is an exceptionally dedicated football player. I suppose in 1995, he came from nowhere and scored some goals in really high-profile games and suddenly had this reputation as a goalscorer.

"Which was true, but he was also a really good playmaker, good at unlocking defences. The ability to take points from out the field was not initially seen as his strong suite, but he took to that part of his game with complete commitment."

Crean was up in Clones last summer to see Dublin play Derry. When Sherlock, out of the team for a considerable period, made an appearance, the reaction in the blue section of the crowd was evangelical.

He holds a curious place in the affections of his home city. One of the most heavily scrutinised and analysed Dublin players of modern times, he is no stranger to criticism and was still becoming accustomed to the fame 1995 brought him when he was exposed to the darker moods of Irish sport.

Over Christmas that year, he was heckled off the field playing for UCD in a league of Ireland game against St Patrick's, a match in which he was singled out for heavy treatment. Walking off the field, he stooped for an instant to mime the throwing of mud toward the hecklers, but stopped short. He was always above responding in kind to base taunts, dealing with ill-natured comments and gestures with maturity and dignity.

Being spat at by a county board official was the nadir of several such incidents. But he has always generated a massively warm reaction among the Dublin cognoscenti, to whom it has become apparent that his commitment to the cause was total and completely separate to his parallel life as a GAA player whose appeal transcended that of the association to which he was bound.

A decade on, Sherlock remains one of the most marketable GAA players in the land but has, understandably, become a more guarded person in recent years.

"The thing about Jason is that he is a gentleman," says Carr. "Any success he has, I am delighted for him . . . always am, because I know what he puts into this and he is someone that has always been a pleasure to work with and to know. You couldn't begrudge him."

But Sherlock's refusal to follow the line of faux modesty that is like a code of honour in the GAA has guaranteed a chorus of grudges over the years, both on and off the field. Offers unusual to a GAA star - advertising and television work - came his way post-1995 and his mere willingness to give things a go was grist to the mill of those who felt he needed taking down a peg. With Na Fianna and Dublin he has taken physical and verbal abuse. It comes with the territory.

"During our Leinster campaign, Jason often came in for a bit of stick, there was the sense that he was singled out by other teams," says his Na Fianna team-mate Karl Donnelly. "But that kind of thing doesn't bother him in the slightest. He just keeps playing his own game."

Donnelly has known Sherlock since their school days together in St Vincent's. A celebrated basketball player, Donnelly was two years ahead of Sherlock and his initial impressions of him were predictable: he was just a cocky, likeable up-and-coming point guard who hung around with his brothers Dave and Emmet. Then, all of a sudden, he was Jayo.

"That whole time around 1995 was a bit weird to watch because it happened so suddenly and it was as if he had suddenly become a pop star. I can't say if he found it terribly pressurising or not because I simply don't know. All I do know is that he never changed. Even during that whole time, he would regularly show up at Vincent's just for a pick-up game or training and it was the same old Jason. No fuss. Because most of his friends played there and it was the natural place for him to be."

As someone who managed to combine basketball and football at high levels, Donnelly has paid close attention to Sherlock, who excelled at all sports as a kid and translated his hoops skills for the purposes of his football career.

"Like a lot of football players who played basketball, he has really good peripheral vision. He is rarely dispossessed on the field and more or less always takes the right option with the ball. He is a team player. He feeds off other players and tries to encourage their best qualities. And the other thing, which is not often commented on, is that he works incredibly hard covering back when the other team has possession."

This year, Sherlock is vice-captain of the club team. Na Fianna are in the quarter-finals of the Dublin championship and remain a heavyweight in the city game. Sherlock is one of three All-Ireland medal holders in the team (along with Dessie Farrell and Kieran McGeeney) and although he is not a shouter by nature, whatever words he does say carry weight. Donnelly has watched with quiet admiration his friend mature over the seasons from the original teenage sensation to a measured and deeply serious player constantly working on his own game.

Sometimes, on nights when Dublin is freezing and there is no football, Sherlock will show up at the school gym to play hoops for an hour with the Vincent's gang. This summer, he served as best man at a wedding of Gareth Winders, his long-time school friend and team-mate. Although his name went national, Sherlock has always been locally inclined by nature.

The Glasnevin crowd will live his every feint and jink in Croke Park this afternoon, but have long learned not to be surprised by anything he does. There is no doubt his name has been the subject of some serious conversation in Kerry this week.

"Everyone knows the threat he presents," says Carr. "Kerry have a number of very tight man-markers and I expect one of those will be dedicated to Jason."

For, after everything, Sherlock is the figure of luminosity, the one who stands out when Dublin's chances of advancing to this year's All-Ireland semi-finals are assessed. That is a testimony to his staying power as much as anything. In 1999, he said in an interview with this newspaper: "I hate that 'remember him' stuff. I'd hate that to happen to me. Whatever you've got, you've got to make the most of it."

Five years on, it cannot be denied he has remained true to that principle. Even during Dublin's traumatic Leinster championship exit against Westmeath, Sherlock's form was a source of comfort. That threat did not dip in the rain of Carrick-on-Shannon against Leitrim, and against Longford, his intuitive understanding with the reborn Ian Robertson boded well.

Then came Roscommon.

"I suppose it was as good a performance as I can remember Jason giving for Dublin," says Donnelly. "He always had talent to burn and a great attitude and I think that at 28 now the experience that he began to accumulate at a really young age is showing."

In a funny way, for all of the exposure, Sherlock has arguably been underrated. To begin with, attempts to balance his Dublin career with a winter life moonlighting as a league of Ireland striker alienated some traditionalists. Then, when Gaelic football went stern and muscle-bound, he remained waif-like, relying on his guile and speed and bravery to survive. He persevered through the periods when Tom Lyons did not regard him as first-choice material, stoically offering his own subtle contributions with what minutes he was afforded, always working, always honing his game. He has reached a point now where his merits are crucial to Dublin's slow-burning championship challenge.

Kerry and Dublin in Croke Park will always carry echoes of the unforgettable 1970s for the city fans. When he burst on the scene, Sherlock seemed to signal the imminence of a fresh epoch, the boy most likely to make the difference. That the same is true some nine years on tells us all we need to know.