Michael Carrick believes he is fit to wear Roy Keane's shirt

Michael Carrick believes he has finally nailed the critics who claimed he would never fill the void left by skipper Roy Keane at Manchester United.

Carrick inherited Keane's iconic No.16 shirt when he joined United from Tottenham for £18.6million in the summer of 2006, a price considered overinflated for a player who had never before sampled Champions League action.

But after helping United to back-to-back Premier League titles and their dramatic Champions League triumph over Chelsea last season, Carrick said he had proved he could live up to Keane's legendary status.

The Geordie said: "I didn't feel any weight of expectation.

"People were talking about the No.16 shirt, but to me it's only a shirt and it doesn't make too much difference. You've got to go out there and play your games, so it didn't really make too much difference.

"Roy Keane was a legend and I'll take nothing away from what he achieved. He was one of the true greats, not just of United but football in general.

"But that didn't really affect me. I wouldn't be doing my job if it did.

"If you sign for this club you want to play all the time. Once you sample United, you know what it is all about. It's a special place and I found that out pretty quickly." Carrick's impressive form in two years at United saw him rewarded with a new four-year deal worth £70,000-a-week towards the end of last season - and he claims those who doubted his ability had never affected him.

"I'm here to do a job and we've won two titles in my time," said Carrick. "It's pleasing for me, but whatever people say I don't really care about it.

"To win the league in my first year was very satisfying and to do it again this year was even better, to prove it wasn't a one-off and that we were good enough to do it again over a long period of time."

Having won three trophies at United, Carrick, 26, believes the current squad are on the brink of greatness and have the ability to dominate at home and abroad for years to come.

"I'd like to think we could," he said. "It's easy to say, but other teams are getting better all the time.

"It's not easy to dominate Europe. But it's good English teams have been consistent in the last couple of years by getting to at least the semi-finals."

Despite his fine form, Carrick has been consistently overlooked by England boss Fabio Capello, who has not included the elegant passer in any of his first three squads.

United returned to pre-season training this week and head off on July 17 on a 10-day tour of South Africa, where they will play three games.

Veteran winger Ryan Giggs, who picked up a record 10th Premier League winner's medal and broke Sir Bobby Charlton's United appearances record last season, is looking forward to the new campaign.

"Obviously last season ended brilliantly for the team and for myself, and it's good to be back," said Giggs. "Wednesday was just fitness testing.

"On Thursday we had another treadmill fitness test, which is always quite hard, and then we'll start to build things up. Long-distance running gets easier as you get older, it's just the quicker stuff that's quite hard."