The Wales forward is meeting with a specialist in London on Monday to get a check-up on the problem, but boss Roberto Mancini does not think it is serious and hopes to have him back by the weekend.
Joleon Lescott has returned to training and is likely to be on the bench after completing 45 minutes of a training match, but Dedryk Boyata could continue in defence as Vincent Kompany is still struggling with a groin problem and Micah Richards doubtful because of a calf injury.
Patrick Vieira and Adam Johnson are expected to be involved again after impressing in their debuts as substitutes in the defeat at Hull on Saturday, while Roque Santa Cruz has recovered from a calf strain.
Source: PA
Source: PA