The Blues striker was forced to sit out Wednesday nights game against Southampton after aggravating the injury during the warm-up.
Blues are awaiting results of scans on the former Lverpool strikers injury and although manager Steve Bruce feels the injury is not serious he will not be risked in the game at Old Trafford.
Darren Anderton is also a definate non starter against Alex Ferguson's title contenders because of a groin injury whilst new signing Salif Diao has still not recovered from a calf injury.
Late decisions will be made on Stephen Clemence, who's partner is expecting a baby, and Robbie Blake who picked up a calf strain in the 2-1 win against Saints.
On a positive note Tunisian international Mehdi Nafti is expected to make his Blues bow against United.