On-loan Birmingham striker Obafemi Martins will miss the final four games of the season with a leg injury, the club has confirmed.
The Nigerian frontman, who arrived on loan at St Andrews from Russian side Rubin Kazan in January, underwent a successful operation to repair a stress fracture of his left tibia on Thursday and is now facing up to four months rehabilitation.
Martins, who scored the winner for the Blues to seal their Carling Cup final victory against Arsenal earlier this season, last featured as a second-half substitute at Wigan in March.
Birmingham boss Alex McLeish admits the injury to 26-year-old former Newcastle man Martins, who has made six appearances in total for the Blues, is frustrating as his side battle for Premier League safety.
McLeish told Birmingham's official website: "It's a blow for Oba and very frustrating for him and us. We all wish him a quick recovery.
"He passed his medical and everything was fine for six weeks, but then it became obvious to us that something was not quite right.
"He started to feel his groin and then this problem crept up on him over the past month or so.
"The head of our medical department, Dr Ian McGuinness, carried out extensive tests and the stress fracture was diagnosed."
He added: "It's a shame we haven't seen Oba at his very best.
"We brought him here in the hope that he could help the team and, of course, we all know what he did in the Carling Cup final.
"The run he had after the goal, when he went round the goalkeeper, that's the explosive pace he has got and the kind of thing he can do, but unfortunately we haven't been able to see it regularly.
"He's had a couple of niggles and obviously the stress fracture needed to be addressed. It's unfortunate, but these things do happen."
Blues were understood to have an option to buy Martins for around £4million when he made the temporary switch to St. Andrews.
He will remain with City until the loan spell expires at the end of May, but it remains to be seen whether the move will now go ahead.
Birmingham, currently 15th in the table and four points clear of the drop zone, entertain Midlands rivals and fellow strugglers Wolves on Sunday as they bid for top-flight survival.