Birmingham striker Nikola Zigic will undergo a new treatment programme this week in a last-ditch bid to regain fitness for the Barclays Premier League run-in.
Alex McLeish's £6million capture from Valencia last summer has scored eight goals this season, including the opener in the Carling Cup final win over Arsenal.
But he has been troubled by groin and hip problems for the past two months which have restricted his appearances.
McLeish said: "It has been a bit of a nightmare with Zigic. The medical team have done what they could but he keeps kind of breaking down and it is too painful for him to continue.
"We can't get anything out of a player who is showing he is restricted when he is making his movements.
"Zigic needs to be able to move freely. He needs to be able to jump to get the best from him.
"We have seen specialists. We feel he is close to playing.
"But we are trying one or two other things the next couple of days to see if we can get him to participate in at least one or two of the games.
"It is different levels of treatment."