Three months have passed since Sol Campbell was released by Newcastle following a "difficult" season at St James' Park for the defender, but on a sweltering August afternoon in west London there is little sign of him missing life in the spotlight.

Appearances can be deceptive. Relaxed he may be as he stretches back and sips a cappuccino in an Italian restaurant, but the 36-year-old is also restless, keen to prove that after a career stretching close to two decades he still has one more season left in him. And as Arsenal supporters head to Old Trafford on Sunday, lifted by their teams' midweek triumph over Udinese but still in crisis mode and pleading with their manager to add experience to a youthful squad, there comes an uplifting message from a player who helped shape Arsène Wenger's Invincibles.

"It would be nice to go back to Arsenal, for sure," says Campbell, who left the club in 2006 following five trophy-rich years only to return for a four-month cameo in January 2010. "I trained there for a month [after leaving Newcastle in May] and have been doing regular fitness work on my own since. We've just come back from a holiday in Portugal and I was even working out then. So I'm not too far behind, all I need is two or three games to regain my match fitness.

"Offers have come my way but after what happened at Newcastle [Campbell appeared just eight times for the club during an injury-hit campaign that also saw Chris Hughton, a close friend and the manager who signed him last summer, sacked in December and replaced by Alan Pardew], I want to make sure I'm truly wanted by a club and that they understand the value of having me; that I can pass on my vast reservoir of skill and knowledge to the youngsters who are there already while playing at the same time. I know a hell of a lot about football and feel I can contribute for another year."

As "sign me up" pleas go that sounds pretty definite, but Campbell insists that while he wants to get back playing he is not anxiously waiting for Wenger to beckon him for a third spell at Arsenal, nor despite remaining in contact with the Frenchman have the pair spoken about a return. But assistance is on hand to the man who helped define Campbell's career and who faces Manchester United tomorrow knowing a second defeat in three league games will see Arsenal, shorn of Cesc Fábregas and Samir Nasri, record their worst start to a campaign since the 1991-92 season.

"Arsène's going through a tough time, but the guy's got loads of experience and knows better than anyone that football is like the sea and occasionally you've got to ride through a storm," Campbell says. "It's mainly been plain sailing for him and now there's some rough waters, but Arsène's no quitter and he'll get the club through.

"Saying that, Arsenal definitely need a few players to come in and shake things up; guys who are really passionate about winning and won't accept failure. The fans want that too, they can see that Arsenal are close to being the best club in the world, they've got everything there, it just needs people to ruffle some feathers."

Occasional disharmony certainly appears crucial to the success Campbell enjoyed at Arsenal the first time around, arriving as a controversial free transfer from Tottenham Hotspur in 2001 before going on to win two Premier League titles, three FA Cups and score in a Champions League final – not to mention finishing the 2003-04 season unbeaten – before joining Portsmouth in August 2006.

"The blend was perfect," he says. "We had clever guys, quick guys, skillful guys, but we also had warriors who gave everything on and off the pitch. We'd have meetings after a bad result or a bad performance and no one would shirk away from criticising a team-mate if they had to. But no one got upset because we realised that had to be done if the team was going to be a success. That's maybe missing from Arsenal at the moment. They've got the footballers but not the warriors, guys like Tony Adams, Martin Keown and Patrick Vieira, guys who could play but who also had that never-say-die-attitude. Those sort of players are out there, Arsenal just need to find them."

A towering and still lean figure, Campbell could well be the warrior Wenger decides to call upon. In the meantime, the man who also has 73 England caps and one appearance for Notts County to his name, insists he has enough to be getting on with. Having married the interior designer Fiona Barratt last July the pair are now occupied with raising their 11-month old daughter, while Campbell also continues to support the Show Racism the Red Card campaign.

"I've been involved with it since 2000 and always help out when I can," says Campbell, who in May handed out commendations to children who had put together films promoting the work of the organisation. "The campaign has done a fantastic amount of work to try and eradicate racism from our game. When I first started playing [in 1992], you'd hear racist chanting at every ground you visited but because of the way 'Show Racism' has got players, clubs and fans to back their cause over the years, that is hardly the case any more, certainly in the Premier League. You still hear the odd chant lower down the leagues, but it's rare and mostly down to a small, brainless minority."

In Campbell's company it is impossible to discuss "brainless" chanting without referring to his toxic relationship with Tottenham supporters, the bulk of whom have still not forgiven him for leaving them to join the enemy a decade ago. Campbell has received a torrent of abuse whenever he has returned to White Hart Lane since and in September 2008, while playing against Spurs for Portsmouth at Fratton Park, was the victim of abuse so abhorrent it led to two supporters, one of whom was only 14, being found guilty of indecent chanting and punished with three-year banning orders.

"It's very sad," says Campbell. "When I left Spurs I was one of the best defenders in the world and had done so much for such a long time with ultimately little reward. I practically kept the club up on my own for two years. Given that, you'd think the Spurs fans would get off my back. I understand them having a problem with me moving to their rivals, but it was a purely professional decision. Arsenal had a ridiculously good team at the time and I knew I'd win trophies there. I have no regrets."

Can Campbell envisage a time when he could return to White Hart Lane and not be the subject of abuse? "Maybe in 50 years, maybe never. Who knows."

A return to the Emirates is more conceivable and, aware of Campbell's interest in coaching, Arsenal have already offered him the chance to help train the academy and reserve teams. "That definitely interests me and I'm giving serious consideration to doing it," he says. "In terms of playing for the first team again — you never know how life will work out. The club know where I am.