Berbatov and Brown will be missing for Saturday's trip to Aston Villa
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.
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