Bulgarian international and Manchester United forward Dimitar Berbatov is likely to undergo knee surgery. The recurring injury kept the Bulgarian out of the 1-1 draw with Birmingham at St Andrew's on January 9 2010. United missed the opportunity to leapfrog over Chelsea at the top of the English premiership – the Londoners are still in pole position with 45 points from 21 games, while the Red Devils are trailing one point adrift but with a match more.

"Dimitar wanted to play with it but we felt we should try to get it (the knee) sorted and get him fit again. He may have to have an exploratory operation," United manager Alex Ferguson was quoted saying by English media.

Regarding the match itself and the disappointing result for United, Ferguson added for the club's website: "It was a sickener but it's important not to let your head go down. We kept battling away and deserved a point."

Berbatov was part of the United side that famously lost the FA cup tie 0-1 to Leeds United at Old Trafford on January 3. Although Ferguson had reshuffled the side following the battering of Wigan earlier that week, the Bulgarian, together up front in partnership with Wayne Rooney, were enable to provide the firepower needed to eliminate a side which was 42 league places further down the pecking order at the time of the clash.

But although some reports had surfaced in Bulgarian media saying that Berbatov's absence from the Birmingham fixture was down to retribution, Ferguson has stood by his player and said that Berbatov being sidelined was purely down to a recurring injury.