Mark Hughes has revealed that Kolo Toure, Martin Petrov and Wayne Bridge will not face Scunthorpe on Wednesday.
Manchester City are set to face the Championship outfit in the fourth round of the Carling Cup.
They will, however, tackle the contest without three of their senior stars.
Blues boss Hughes has admitted that he expects to have a full-strength squad for Sunday's trip to Birmingham, but he is not prepared to take unnecessary risks in midweek.
"Kolo is not fit, Martin Petrov is not fit and we have a slight doubt over Wayne Bridge, so he might not be involved," Hughes said.
"Hopefully they will be okay for the weekend but they're not quite right at the moment. They went for scans yesterday, there was nothing too serious but tomorrow is too soon for them."
Hughes is intending to field a strong side against the Iron, with the Carling Cup presenting City with an ideal opportunity to get their hands on some long-awaited silverware.
"I've gone strong in terms of team selection in the previous rounds and I see no reason why we should change that," he added.
"The injuries will affect the selection. There might be a few senior players who haven't had a lot of football of late, we might introduce them. But there won't be a raft of changes. We want to progress in the competition and it's important that we do."
One of those hoping to be included is Roque Santa Cruz, with the Paraguayan having been severely hampered by injury since arriving at Eastlands over the summer.
Hughes said on his South American striker: "We need to check him out because he has missed a bit of training. He trained yesterday, we took him out half way through, and hopefully he will train again this afternoon and feel better in himself. Hopefully he will be an option."
Hughes has also responded to reports from Spain suggesting that Robinho is keen on a move to Barcelona.
The Brazilian playmaker is said to have expressed a desire to secure a switch to Camp Nou in order to further his career.
Hughes, though, insists he has not seen the quotes in question and claims his Samba star is often misrepresented in the media.
"Sometimes Robby gets asked questions and he is very open in the way he answers at that point in time," said the Welshman.
"But more often than not, the answers are out of context. Until I see what he has said I can't really comment."