Gareth Barry is such a stone-cold certain selection for England's World Cup squad this summer that he might as well start packing for his flight to Johannesburg now.

Bercks appeal: Gareth Barry will miss the presence of David Beckham in England's dressing room at the World Cup

But the Manchester City midfielder only needs look at the agonies that last week afflicted David Beckham, his mentor in the national side for seven turbulent years, to think better of it.

Even if Beckham does travel to South Africa as a glorified cheerleader, his absence from Fabio Capello's dressing room with a ruptured Achilles threatens to hurt Barry more than most.

Beyond the pair's strong dynamic on the road, Beckham acted as an effective mentor to his younger team-mate when Barry endured a prolonged England exile, frozen out of the national side for almost four years after Sven-Goran Eriksson had chosen him to play a friendly against Serbia in June 2003.

"He helped me when I had the big absence from making squads," Barry says. "When he spoke to you, he gave you more encouragement. He knows the right way to speak to people, and when to do it. I've been in a lot of squads with David, I know him well. He's a good bloke to have around, so it's a sad loss."

It seems strange to imagine Barry on the margins, so transformed have his England prospects been under Capello. Indeed, in this ever-changing environment, the 29-year-old has established himself among the few hardy perennials, featuring in every one of the Italian's squads until suspension ruled him out of the qualifying win over Andorra last June.

Having experienced every aspect of the head coach's uncompromising approach, he knows that he earned such faith.

"You've seen already that he picks players on form rather than reputations, so I certainly trust his decisions there. Since he has taken over, I've never been regarded higher as a holding midfielder, and the things I've learnt there have made me realise more about that role and I've taken that on here at City. The Italian mentality is about defending and concentration, so I feel like I've learnt a lot."

Happily, it is a philosophy augmented with his work with Roberto Mancini at his club. Do not assume, though, that his privileged status as a Capello favourite brings him any closer to a personal understanding of the man in whose hands his World Cup ambitions rest.

"I don't know him any better than the first squad," admits Barry, a little out of breath after walking the 'Mancini Mile' on behalf of Sport Relief.

"He doesn't give too much away to the players – he'll let you know what you're doing right or wrong but apart from that, the relationship is professional."

Barry exudes a disarming serenity, borne evidently of his conviction that he is the one City player poised to represent his country in the tournament he has been in love with since Italia '90.

Shaun Wright-Phillips and Adam Johnson should both be deemed outsiders in the wide positions, while Wayne Bridge controversially declared his involvement to be "untenable", leaving Barry, potentially, as the one World Cup representative from Eastlands.

"I'm never one to boast, or to say that I'm 'nailed-on', but having been in the majority of squads, I'm confident that I can make it. You have to have confidence in yourself."

The Bridge saga was a testing one for Barry: with a foot in both the City and England camps, he risked being caught as the man in the middle, forced to explain to Bridge why he should not turn his back on the World Cup despite the presence in South Africa of John Terry, revealed as having had an affair with Vanessa Perroncel, the left-back's then girlfriend.

"It was a bit awkward for me," he concedes. "But you have to put that aside. I would like to see Wayne go. Time can change people's opinions sometimes and I hope that will happen with Wayne. He doesn't want to sit down in a few years' time and regret anything so I'm, so I hope he will change his mind.

"He has been to a World Cup before and knows what it's all about, so his decision will be the final one. It might be a last time to do something."

Barry and fellow City allies could, he hinted, be preparing another attempt to persuade Bridge to relent, even though there has been no softening yet.

"He's injured at the moment, so I've not seen him at all – but prior to that his decision was still the same. I think there have already been conversations with the lads to see what his mindset is, and there could be a see what he is thinking and you may put an opinion across."

Expect Barry to convey the same opinion that always motivated Beckham: patriotic duty comes first.