Birmingham manager Alex McLeish has revealed that Garry O'Connor is set to be sidelined until March.
The Blues striker is facing another operation due to complications that have arisen from a groin injury.
He underwent surgery last season but has continued to struggle with his mobility and will now go back under the knife.
McLeish has confirmed that O'Connor will be out of action for some time, leaving Birmingham short of options in attack.
"In all likelihood, the big 'un has got to go for an operation and we could be talking three to four months," McLeish told the club's official website.
"That is the kind of road we're going down, so it's another man down.
"He's basically someone who gives us a wee bit of a presence and otherwise we lack that."
Birmingham have suffered another injury blow with the news that midfielder Teemu Tainio may also need an operation.
The former Tottenham and Sunderland man has regularly been unavailable since moving to St Andrews over the summer and McLeish has decided it is time to take action.
"He has had ongoing problems with his knee," said McLeish.
"We knew he had a little bit of trouble with his knee before he came to us, but we thought we could manage it.
"But, unfortunately, he's been missing more than he's been available. I think he might need to get it tidied up."