Capello was pilloried following England's disappointing World Cup this summer and only last week the UK's biggest selling tabloid depicted the England boss with donkey's ears alongside the headline 'Jackass'.
However, with England set to play their first competitive match since the World Cup debacle - against Bulgaria at Wembley on Friday - followed by another qualifier in Switzerland on Tuesday, Barry insists the squad are united.
"Everyone is right behind the manager," said Manchester City midfielder Barry. "I firmly believe the players and manager can go on and do great things. He is still the man to take England forward."
Although it has been suggested Capello is determined to adopt a less intense approach, Barry has not detected a notable change. The midfielder says the demand remains for England to play to their strengths, even if it was precisely that which led to such a let-down in the summer.
"I have not noticed anything different," he said. "He still wants us to play at a high tempo but the whole squad is pretty relaxed. Everything is pretty chilled there so there are not too many changes.
"We just want to get the results right. That is going to be what makes people happy."
But there have been some changes. The move to Friday night internationals means Under-21 coach Stuart Pearce is not around to exert his influence.
David James and Emile Heskey are notable omissions from the men who were on duty at the World Cup, their international careers finally over.
And, even though Jack Wilshere has been relegated back to the Under-21 fold, Arsenal team-mates Theo Walcott and Kieran Gibbs bring youth to the present set-up, as does Adam Johnson, who has been hugely impressive since swapping life in the Championship at Middlesbrough for a shot at glory alongside Barry at big-spending City.
"Adam could really make his mark," Barry said. "He joined us in the middle of last season, came into the team full of confidence and hasn't stopped since. He has kept improving with every game. The more he plays at this level, the better he will become."
After making his first start against Hungary, Johnson could well be asked to make his competitive bow on Friday, especially if Capello opts to select Wayne Rooney as a lone striker and utilise two wide men.