Ashley Barnes is set to miss several weeks after picking up a calf injury against Swansea City.
Head coach David Wagner confirmed that Barnes had not damaged one of the major calf muscles but would still be out of the picture unless Norwich City progressed to the end of season play-offs and reached the Wembley final.
"He has a calf injury. Luckily, it's not a major muscle so we won't rule him out for the rest of the season. He could be back for a play-off final if we get that far. He'll work hard in the treatment room with the medical department," Wagner said.
"We'll use what we have. In the last game, we were quite good offensively, we maybe didn't score as much as we should have. I have confidence in the team to do it without Barnesy if needed.
"We have the options in our squad, several players who can play in several positions. We'll find solutions."
Greece international Dimitris Giannoulis has returned to full training while club captain Grant Hanley has another week under his belt.
Wagner also outlined that the long-term injured players are still playing their part around the Lotus Training Centre as the squad aims to secure a play-off spot.
"Dimi is back in training, if everything goes to plan he'll be back in the squad on Saturday. Grant has had a second week now as well. Everyone else was fully involved.
"Onel (Hernández) plays a big part, (Liam) Gibbs is in the canteen every day. There's been periods where not everyone believed in them but this group's commitment is extraordinary. Players who can't help on the pitch are still playing their part."
With Saturday's opponents in danger of relegation, Wagner outlines that his focus, and that of his squad, is solely on what they can achieve themselves.
"We want to play competitive games and win them. It would be the same if we were safe mathematically. We want to finish as high as we can - it's the same from matchday one to matchday 46," he explains.
"It's a big test for us, to show how calm we can be, to keep our cool.
"From the tactical approach, Birmingham use a different set-up that possible play-off contenders would use. In terms of occasion, the focus on the game is comparable which is good for us to experience. We want to do our job on Saturday.
"To be involved in such a big game, where it counts, is good for us. Everybody needs to keep their sharpness and concentration at the highest level.
"We have something big for us to be focused on, not on what's going on at Birmingham."