Alex McLeish admits the Birmingham medical staff will be working around the clock ahead of the crucial Premier League clash at Wigan.
Barry Ferguson and Martin Jiranek joined the Blues' lengthening injury list when they both left the field in the opening half hour of the FA Cup defeat against Bolton.
The Carling Cup winners already have several key players sidelined as they look to stave off the threat of relegation.
But McLeish is hoping Ferguson and Jiranek, along with other important first-team stars, will return for next weekend's potential six-pointer at basement boys Wigan.
He said: "We thought Barry had pulled his muscle but we believe it's just a dead leg.
"The doctor thinks that he should recover from that given he's just recovered from a rib injury that would have kept other players out for a couple of months.
"Jiranek got stamped on by Stuart Holden but it wasn't intentional.
"When a guy like that signals he needs to come off, then you know it's something serious.
"We'll be guided by the medical guys over the next couple of days and they're all in round the clock in terms of their treatment.
"We believe that one or two will have benefitted from this bit of respite because there were a few waiting to explode muscle-wise."