Sol Campbell has ditched the suits, open-necked shirts and espressos and has his tracksuit back on.

He has tried his hand at politics and dabbled in business, but the former England, Arsenal and Tottenham defender is ready to return to the game that made him a star.

Campbell came close to running as Conservative candidate for London Mayor and has helped run his wife Fiona's furniture design business since he retired in 2011, yet he can no longer ignore the nagging feeling that he has unfinished business in football.

Sol Campbell has been out of football since 2011 but now says he is ready to return to the game

Campbell most famously lined up for Tottenham and Arsenal in a near 20-year playing career

Campbell considers punditry the easy option and wants to be 'on the edge and making a difference' on the training pitch and the touchline.

Over an hour and a half he is bursting with ideas and opinions on how he could do that, starting with much-troubled centre back John Stones, the Manchester City player who faces Campbell's old club Tottenham on Saturday.

'Let me get up to Manchester City and help Stones out, turn it around for him,' Campbell says. 'I could probably turn around Stones in a couple of months. He's made mistakes because he's doing too much. It's all about recognising that. If that's the way I get in to start off, that's what I want to do. I'd love to do that.'

Campbell's hands whirl and flail with enthusiasm as he adds: 'Vincent Kompany would be a big thing for him. Stones can learn from him. That's how you learn, with the manager and with good players around you.

'If you're clever as a young player you listen and you watch other top players in your position. You ask questions, you see how they deal with scenarios. As a top player, you have to do that as well, play your game but coach others around you.

The 42-year-old believes he could turn John Stones' career around in 'a couple of months'

Campbell speaks to Sportsmail's Sam Cunningham as the pair wander the streets of Battersea

CAMPBELL'S CAREER 1992-2001: Tottenham Hotspur 2001-2006: Arsenal 2006-2009: Portsmouth 2009: Notts County 2010: Arsenal 2010-2011: Newcastle 1996-2007: England (73 caps) Advertisement

'Stones needs teaching. OK he cost £50million but that's not his fault — he needs someone to go through motions and scenarios and battles with him. Go through easy games and make sure you're still on it.

'Sometimes you think it's an easy game and that's when you're most vulnerable. As a defender you've got to always be alert' — he clicks his fingers — 'you've got to be expecting the unexpected and I don't think he's doing it now.'

Campbell learned from Tony Adams and Martin Keown at Arsenal but earlier on in his career, when he was closer to Stones' 22 years, Gary Mabbutt taught him at Tottenham what commitment means. Mabbutt was a diabetic and had to take a prick of blood from his groin and run it through a machine to test his sugar levels before games, at half-time in the dressing room and afterwards.

'Seeing how much he had to do just to get through a football game was incredible,' Campbell says. 'For him to play for such a long time under that pressure as a diabetic and the pressure of football is remarkable. He managed it very well. Sometimes, in hotel rooms, it was quite hairy but he got through it.'

Campbell learned a lot in his early playing days from Tottenham team-mate Gary Mabbutt

He lays out plans to become 'one of the greatest managers this country has ever produced'

Let me get up to Manchester City and help Stones out, turn it around for him. I could probably turn around Stones in a couple of months

We meet for a coffee at a small cafe in Battersea Park, where he lays out his plans to become 'one of the greatest managers this country has ever produced', combining different facets of the other worlds he has experienced.

From politics, Campbell explains, he learned the art of rhetoric, of not only being convinced of an idea in his head but of articulating it to convince others.

From business he learned that 'every penny counts', the importance of detail and spotting opportunities for the right deals. 'If you haven't got the budgets of Arsenal, Manchester City or Chelsea you have to think like that,' he says.

All of this, he feels, makes a modern-day manager, but he concedes that his reputation as a player counts for nothing. 'An 18-year-old, coming up through the ranks, probably won't recognise me,' he admits. 'I think they'll know Sol Campbell, but won't know the performances. They might've seen me on Premier League Legends, but generally I don't think an 18-year-old will.'

Central defender Campbell won two Premier League titles with Arsenal, in 2001 and 2004

He says his wife Fiona is prepared for life to change should he take up a position as a manager

Many others still do and as we take a stroll through the park later a man shoots by on a bicycle and shouts 'Sol!' on his way past.

Campbell has enjoyed being able to bring up a young family relatively out of the spotlight — he has three kids aged one to five — but Fiona is prepared for all that to change if he is successful and so is he.

'I'm older now,' says the 42-year-old, who has a dusting of grey in his light stubble. 'I'm even more mature than I was as a player. I can handle all that kind of stuff. I dealt with it as a player and it's a little different as a manager but I've got the capacity to absorb all of that.'

His wife also accepts that he may move abroad, or be stationed at some League Two outpost and as he slops through the rain and mud he points out: 'This could be what my first training pitch is like!'

Campbell believes he is more mature now having retired, and says he can absorb everything

The former England international ended his playing career at Newcastle United back in 2011

To get here, Campbell spent three and a half of his five years since retiring completing his UEFA badges with the Welsh FA and as part of the programme the coaching hopefuls must spend a fortnight abroad shadowing a club.

Campbell picked up the phone to former Arsenal team-mate Dennis Bergkamp, who is assistant manager at Ajax. 'He's still the same Dennis — legend,' Campbell says. 'He came from the rough streets of Amsterdam. He knew everything; the little stamps on the feet, everything. He was such a strong player. A top man, though.

'Ronald De Boer is there. Marc Overmars is the sporting director. I watched training sessions, studied the youth system, spoke to them all about how it was run.

'I've the burning desire of unfinished business in football. I'm ready to roll my sleeves up and get stuck back in.'

These shirt sleeves don't come with cuffs.

He says he has the 'burning desire' for unfinished business and wants to roll his sleeves up