Manchester United could be without first-choice center-halves Rio Ferdinand and Nemanja Vidic when they take on Roma in the Champions League on Wednesday. The absence of Vidic is definite after the Serbian injured his knee in the first leg and is set for a three-week layoff, while Ferdinand remains a major doubt. The England center-half limped off United's 2-2 draw with Middlesbrough on Sunday with a foot injury, but scans proved that there was no fracture. However, Sir Alex Ferguson is unlikely to rush him into action, as Wes Brown and Gerard Pique will probably link up at the heart of defense. Chance Spanish defender Pique is glad to get a chance of starting against Roma, as he indicated that the team shouldn't be missing the Ferdinand-Vidic pairing. "I'm ready, I've waited a long time to get a chance in a game like this. It's what I dreamt of when I left Barcelona," he said. "It's been frustrating because the manager told me in the summer that I would figure in his plans but Rio and Vida have been playing so well that I haven't had a chance. "We are more mature as a team this season. People said we struggled last year when Rio and Vida were injured and we were knocked out of the Champions League by Milan but I think we are stronger now." The former Barcelona man earned praise from Ferguson, who described him as 'absolutely terrific' during the Boro draw.