Birmingham manager Steve Bruce has revealed that Tunisian midfielder Mehdi Nafti is likely to miss the whole season because of a knee injury.
Nafti tore a cruciate ligament against Deportivo La Coruna last weekend.
"It is a terrible blow for Mehdi and we all feel for him - he was looking really good in pre-season," said Bruce.
"As for whether he's out for the season, you would have to think so. We just wish him all the best and hope that he can have a speedy recovery."
Bruce added: "It seemed an innocuous challenge and we thought he'd got away with it - after all, he was able to walk onto the plane on Monday. "We have to look at our options as regards replacements, which is difficult as we've only just heard the news and I haven't even thought about it yet."
Nafti, 26, joined Birmingham on a permanent deal after spending the second half of last season on loan from Racing Santander.
Birmingham's season was derailed last year when Mikael Forssell, Muzzy Izzet, David Dunn and Stan Lazaridis all suffered serious injuries.
Bruce said: "It sums up the last 12 months for us. Nobody has suffered long-term injuries the way we have, after the way we lost Mikael Forssell, Muzzy Izzet, Dunny and Stan Lazaridis last season.
"With Mehdi now, no other Premiership club have suffered five major injuries like that."