On the Premiership: Sol Campbell has endured humiliation and examination during the past week, but he will hope today marks the beginning of his footballing redemption. The Arsenal defender is due to meet his team-mates at their Hertfordshire training complex this morning for the first time since he fled Highbury in the wake of a distracted and disjointed performance against West Ham last Wednesday.

He will not lack support. Football's insularity may occasionally infuriate, but few industries are more diligent in protecting their own and Campbell is assured a warm welcome. Thierry Henry, as influential to Arsenal's attack as Campbell is to its defence, has already promised when the 31-year-old walks into the dressingroom, "my arms will be open ready for him". But while Campbell's colleagues will be sympathetic to his plight, they will also be confused as to how he could have fallen so far so quickly.

On the surface, his problems seem to stem from a straightforward loss of form. Campbell's performances have been riddled with uncertainty for some time, but he touched a new nadir five days ago when Arsenal crumbled against their London rivals.

Neither was this merely an off-colour night: Campbell made the sort of pratfalls which end up on Christmas blooper videos. Having spent most of his career fending off the threat of the world's best strikers, Campbell's pride will have been stung by being made to look foolish by Nigel Reo-Coker and Bobby Zamora.

But it is not as simple as that. Campbell's problems cannot be solved by merely putting in an extra hour of defensive practice on the training ground: they are deep-rooted, personal issues which affect a sportsman's most precious commodity, his mind, and which could prove terminal if treated clumsily.

There is an obvious paradox in Campbell - the archetypal rugged centre-half - having his sensitive soul exposed, but then again he has always been a bundle of contradictions. This is the boy from a north London council estate who now earns £80,000-a-week at one of the most famous football clubs in the world; the man who shrugged off the vile abuse heaped on his broad shoulders by Tottenham fans in the wake of his move to Highbury in 2001, but whose mind now appears to have been scrambled by off-field events.

The nature of Campbell's concerns has inevitably been the subject of frenzied conjecture ever since he sped away from Highbury with the jeers of West Ham fans ringing in his ears. Gossip and tittle-tattle have provided an unedifying soundtrack to Campbell's life from the moment he exploded into the Premiership with Spurs in the mid-1990s and those rumours have now resurfaced with a vengeance.

Internet message-boards are bulging with hearsay; the red-tops have launched into a feeding frenzy over whatever scraps of information they can lay their hands on.

Supposition is inevitable in such situations, but with Campbell it is also necessary. He guards his privacy as jealously as he protects Arsenal's goal and despite the fact he has been resident at the summit of the English game for over 10 years, we still know very little about him. Campbell hardly ever talks to the media, written or broadcast, and when he does he chooses his outlets warily.

It was, however, in an interview given just before last year's FA Cup final that Campbell illuminated one aspect of his deeply complex character. He was reflecting on the struggles undergone by athletes who are robbed by injury of their lifeblood of regular competition, a war he has waged for most of the last two seasons.

"The game gets me through a lot of things," he said. "That's why I have been suffering. If you're not playing, not training, you have a lot more time to think."

A little thinking is a dangerous thing, and Campbell's manifold fitness problems have given him plenty of time to do it over the past year. It is possible that the weeks of rumination have shrunk football's significance, especially as in the last 18 months he has also had to contend with the death of his father and the imprisonment of his brother, John, for assaulting a student who had accused Campbell of being gay.

It would be no surprise if these two seismic events had clouded Campbell's focus, especially as he has always attempted to maintain an emotional distance from football. He has made no secret of his desire to explore other interests, including acting and even architecture, once his career has dwindled to a close.

"It's absurd to assume footballers don't want to improve themselves," he observed in another of those rare interviews. "One day I want to go to new places and learn new things." No matter how affectionately he was received by his Arsenal team-mates this morning, that day must now seem nearer than ever.