Birmingham City striker Mikael Forssell is facing a month out after discovering he needs a hernia operation.
He said: "Mikael will go into hospital on Monday. It looks like he has got a hernia problem and we will do something about it as quickly as we possibly can.
"He will miss the Manchester United and Blackburn games but, with the two-week international break coming up soon, hopefully he will be back available after that. These things usually take three to four weeks.
"This season, he came back looking sharp and we wondered if he was finally over everything and this will be another blow to him."