Manchester City winger Martin Petrov could be sidelined for up to four months as he is facing a knee operation.
Petrov's injury - which occurred on international duty with Bulgaria - failed to respond to treatment and is scheduled to return to Spain next week for an operation.
City manager Mark Hughes said: "Martin is going to see a surgeon on Monday and he will probably stay and have an operation. If that is the case he will probably be out for three to four months. That would be a blow for us as he gives us more options."
He added: "Unfortunately it is a frustration for us as it happened on international duty. That makes it a bit more difficult to take.
"Martin had a good pre-season and last year he was one of our outstanding performers.
"But at the moment it looks as though he will have to go in for an operation."
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