Dimitar Berbatov & Wes Brown out for Manchester United

Manchester United striker Dimitar Berbatov has been ruled out for two matches, while defender Wes Brown will miss up to five weeks.

Berbatov was substituted with cramp during Bulgaria's 6-1 defeat by Serbia and has a slight hamstring strain.

Brown, 29, last played in the 1-1 draw against Everton at Goodison Park on 25 October and is recovering from an exploratory ankle operation.

United manager Sir Alex Ferguson said the news was "really disappointing".

Brown has endured a long list of injury problems. After establishing himself at Old Trafford during the Treble-winning season of 1998-1999 he missed the whole of the following campaign with a cruciate knee injury.

Despite another knee injury, he recovered to make England's World Cup squad in 2002, before breaking an ankle for United playing in the Champions League in the same year.

Brown has gone on to impress Ferguson and earlier this year agreed a new contract to keep him at United until at least 2012.

Ferguson added: "Fortunately we have plenty of cover at right-back, with Gary Neville, Rafael Da Silva and John O'Shea available to come in."

Berbatov will miss Saturday's visit to Aston Villa and Tuesday's Champions League game at Villarreal.

Commenting on his striker's injury, Ferguson said: "It's not a tear. It's a slight strain but with hamstrings you don't take any chances. There's no point in making it worse."