Birmingham striker Matt Green has been ruled out for the season having suffered cruciate ligament damage in training.
The striker, signed on a two-year deal from Mansfield in the summer, has bagged two goals in 12 appearances for Blues this term.
But he will play no further part in boss Lee Clark's plans and is now set for surgery before he begins lengthy rehabilitation.
Clark told the club's official website: "He is seeing a specialist, who will decide when he does have the operation and also, when he opens the knee up, discover if there is any other damage.
"So we have lost Matt for the rest of the season which is hammer blow to us but, more importantly, a hammer blow to the lad."
Having started the season as a first-choice striker, Green had failed to feature in Birmingham's matchday 18 for four successive games before sustaining the injury in training towards the end of last week as City prepared for their 3-1 victory at Huddersfield.
But Clark has revealed the 26-year-old was again starting to show impressive form before injury struck.
"He has been working extremely hard," Clark said. "It has been a little bit up and down for him. He has had some great highs where he has really looked very good for us. At other times, bridging that gap has been a bit tough. But we love his attitude and for him to have this setback, it's a big blow.
"It (the injury) was done last Thursday in training during the last part of the session. He was looking really, really bright and was coming back into my thoughts in regards to being involved in the 18 on Saturday at Huddersfield but this injury has taken him away from us.
"We have got him and Neal Eardley out now but what I do know is that I have got a terrific medical team who can help those lads come back stronger than they ever were."