Sean St Ledger faces the prospect of more weeks on the sidelines as he battles to recover from injury.
The Republic of Ireland international pulled a hamstring in the 2-0 win over Bristol City at the start of October. But the injury is taking longer to heal than originally thought.
City boss Nigel Pearson admits St Ledger is growing increasing frustrated at his prolonged period on the treatment table.
"It is a longer-term one than we thought, but we will just see how that develops," said Pearson. "It is disappointing to have him missing for so long but that is the nature of this injury. It is hard to put time scales on these types of injuries.
"Sean does get very frustrated because he is the type of character that wants to be training and playing every day, but we are not going to rush him back.
"When he comes back, I want him back 100 per cent."
Pearson said City are still having to manage top scorer David Nugent's neck problem. Nugent suffered the injury in the 2-2 home draw with Nottingham Forest. He then scored a double in the 6-0 victory over Ipswich before being forced to come off and miss the next two games.
He returned last Saturday as a substitute and scored twice in the 4-1 win over Derby, despite being unable to train properly the week before.
Pearson admits City's medical team are still being cautious with Nugent, who has scored five goals in the last three games he has played.
However, Pearson is confident the star striker will be fit to face Barnsley tomorrow.
"He trained yesterday and we will manage that and see if he is available for Saturday," said Pearson.
"Fingers crossed he will be. Because of the nature of the injury we have to make sure we have an open mind on it.
"There will be days when he is not feeling quite right. Hopefully, he and we will manage it so he will be available."
City have no other injury worries and winger Anthony Knockaert, who is the subject of a police investigation into a public order incident last Saturday night, will be in the squad.
