Striker James Norwood is set to be out of action for at least six weeks after tearing a hamstring in training earlier in the week.
The injury is a further blow to Norwood, who spent much of last season struggling with groin problems which required him to undergo surgery twice.
The 30-year-old has only fleetingly played a part in the opening weeks of this campaign - one start, four sub appearances - having spent most of pre-season rehabilitating from his most recent operation in February.
"It’s not as bad as first feared but the scans have shown that Nors is likely to be out for six weeks at a minimum," Town's general manager of football operations Lee O'Neill told the club site.
Norwood’s latest injury leaves the Blues short on strikers with Kayden Jackson not yet fully fit after the groin problem he suffered in training and Aaron Drinan sidelined until mid-November with a thigh issue.
Oli Hawkins impressed when making his full league debut as the cenral striker in the 2-0 victory over Rochdale at the weekend, while youngster Ben Folami is likely to come into the reckoning for a place on the bench given the lack of other fit options.
Manager Paul Lambert could weigh-up whether to make a signing as cover but the Blues are significantly hampered in their ability to make additions by the salary cap and he may in any case believe he has enough options already at his disposal with Freddie Sears also able to play down the middle.
The international transfer window closes on Monday, but clubs are able to complete domestic transfers until Friday 16th October.
News that Norwood had suffered another injury first emerged last night when he was photographed by a fan with crutches in a Stowmarket restaurant with the striker making his displeasure at having been surreptitiously snapped clear.