Dimitar Berbatov missed training yesterday with a knee injury, raising doubts about whether he will be fit enough to make his home debut for Manchester United against Villarreal this evening, but the greater concern for Sir Alex Ferguson came with confirmation that Michael Carrick will be absent for up to six weeks after a foot injury sustained against Liverpool on Saturday proved to be more serious than was first thought.

Ferguson suggested at the weekend that Carrick's injury, which he suffered in a 50-50 challenge with Yossi Benayoun, was not serious, but further examination has revealed that the England midfield player, who left Anfield on crutches after the 2-1 defeat, has a small crack in his right foot.

The club's medical staff expect that the influential 27-year-old will be absent for at least four weeks, ruling him out of England's World Cup qualifying matches against Kazakhstan and Belarus, as well as up to six Barclays Premier League and three Champions League matches. “Michael's injury hasn't turned out well for us,” Ferguson said yesterday. “He has a small crack in his right foot and that means he will be out for four to six weeks.”

Berbatov also suffered an injury at Anfield, jarring his right knee in a challenge with Jamie Carragher, and may not be risked against Villarreal if Ferguson feels that it would be better to rest him in advance of Sunday's trip to Chelsea. “Dimitar has a bit of swelling on his knee and we're working hard on that, but we might be running out of time,” the United manager said.

With doubts over Berbatov, there is likely to be a place in the squad this evening for Manucho Gonçalves, the 25-year-old Angola forward who recently received his work permit, having signed from Petro Atlético in January. With Carrick injured and Paul Scholes suspended for his red card against Zenit St Petersburg in the European Super Cup, Owen Hargreaves is likely to start a game for the first time since the Champions League final triumph over Chelsea in May.