English FA Cup Semi-final: Today Manchester Utd v Watford Venue: Villa Park Kick-off: 5.30pm On TV: BBC 1:Inheriting Roy Keane's number 16 shirt at Old Trafford was never an issue for Michael Carrick, writes Daniel Taylor.

For a player who passes the ball as beautifully as Michael Carrick, it is strange how scepticism has attached itself to him at every club. At West Ham he was thought of as the rosebud that never properly flowered. At Tottenham the fans likened him to Glenn Hoddle, yet complained that he still fell short. And in his early days at Manchester United there was an obsession with his £18 million price tag and serious misgivings about whether he was equipped to take over from a once-in-a-lifetime legend such as Roy Keane.

It is only now, approaching the climax of a potentially seminal season, that the sniping has been replaced by an acknowledgment that Carrick is a United player in the truest sense. His passing ability has never been in question but the issue, wearing Keane's old No 16, was whether he had the authority to take games by the scruff of the neck. Carrick's performance in the 7-1 demolition on Tuesday was so authoritative - including two goals of such exquisite quality they could have been set to music - it should end any lingering debate about his worth.

An audience with the man himself reveals a footballer living out the "stuff of dreams" and totally at ease with his vision of himself in a side bidding to emulate the 1999 treble.

Of Ferguson's squad, only Rio Ferdinand, Cristiano Ronaldo and Wayne Rooney have played more games than Carrick this season.

"I suppose there was always going to be that thing of 'is he worth it?' and 'was it the right thing to do?' But, honestly, the price has never been something I thought about too much anyway," Carrick says. "It was a lot of money but I looked at it the other way. It was great for me to know that a club of this size, and the manager here, was willing to pay that kind of money for me. That gave me confidence from the first day and, if anything, wearing the number 16 shirt is an extra challenge, an extra incentive.

"It has never been a burden. The boss offered me it on my first day and said: 'I'd like you to have it, do you want it?' He said people would see me as a replacement for Keane and that it was a challenge for me to prove myself to people. I just said: 'Yeah, no problem', and that was it, really. I was more than confident taking it. I was well aware of what it meant, obviously, but it isn't something I ever worried about."

Carrick, one quickly discovers, is not lacking self-belief. "Confident" is a word he uses several times and he seems happily oblivious to some of the scepticism that has clung to his career. "At the start of the season people were talking about it (being Keane's replacement) all the time, and understandably so. He was a legend here and there was an obvious gap when he left. But I was always confident in myself. I was confident I would prove myself and hopefully nights like the other night show I am doing that.

"It was never a case of thinking that I had to do certain things to pay back the club or justify the price. I never lay there at night wondering whether I could cope. To me this move seemed like a natural progression.

"I feel like I have improved a lot as the season has gone on and I also think there's a lot more to come. I'm still only 25 and this is my first season at the club. I've been getting better and better and I've scored five times since Christmas, which makes it my best scoring season already. When you come into a new squad with such good players, strong characters, you have to feel your way in and for me it was just a case of settling in and getting to know all the other lads."

He feels his performance against Roma was his best of the season - "but there have been other games when I have done pretty well too" - and he does not seem anxious about the possibility Owen Hargreaves, the man keeping him out of the England team, will be competing with him for the holding midfield role at Old Trafford next season.

"If Owen does join us, it wouldn't concern me at all. This is one of the best clubs in the world, if not the best, and the boss is always going to be trying to improve his squad with top players, and Owen is certainly a top player. It will be another challenge because we could be going for the same position. But it keeps you on your toes and the way it has gone this season things have been changed around in midfield anyway."

First things first, however, and Carrick feels he is reaching his most exhilarating form at just the right time. "It's a different mentality at this club," he says. "The expectation at United is to win every game and you have to be at your very best in training, never mind in the games. There are players here who inspire you by what they have done and what they still want to do. Someone like Ryan Giggs, who has won eight league titles and yet he's still got that incredible drive. Giggs and Scholes are the two who really stand out for me. I see their drive and their enthusiasm and I just want to learn from them."

A season he describes as "tremendous already" should, in theory, usher United into the first FA Cup final at the new Wembley barring an upset by Watford today and Carrick - whose only previous medal is from West Ham's FA Youth Cup-winning team - exudes boyish excitement about the possibility of the treble. "These kind of opportunities don't often come along and we really have to make the most of it," he says.

• Guardian Service