Midfielder Luke Hyam is facing up to another four months on the sidelines having undergone surgery on the knee injury which has kept him out of action since January.
"Sadly we’ve lost Luke Hyam to injury,” manager Mick McCarthy told the club site from the squad’s training camp at the Carton House Hotel in Co Kildare in Ireland.
"He’s suffered a setback and could be looking at three and a half to four months out.
"He’s rehabbed twice now and he’s had surgery this morning [Friday]. Hopefully that will get him right but it’s a big loss for us and my heart breaks for him.
"You’d be disappointed for anyone to get an injury like that but for it to happen to such a good, hardworking pro is really sad. He will be a big miss for us and he was really upset when he had to leave the training camp.
"We wish him a speedy recovery and hopefully he can be back sooner rather than later, we want him back fit playing for us.”
The 23-year-old initially suffered the injury in the FA Cup replay against Southampton.
The Blues seem certain to look for another central midfielder given Hyam's continued absence.
Town start their pre-season friendly programme this afternoon with a game against Shelbourne at Tolka Park, Dublin (KO 3pm). Meanwhile, the U21s are in action at Leiston (KO 3pm).