The striker, who has been in fine form, took a blow from a team-mate in a training ground accident but he is not sure of the extent of the injury. The swelling has not gone down and there may even be a crack on his side. With Cole feeling discomfort he may be rested for the next few matches as he risks a long-term lay-off if he aggravated the injury.
The England hopeful was caught in a freak incident at The Cliff last week. He was in pain at the time, but it is still troubling him and medical staff are waiting to establish the extent of the problem.
Sir Alex Ferguson, United's manager, left Cole out of the squad for the match away to West Ham United on Saturday and he could be rested for the next two or three matches. United are in the enviable position of having plenty of options up front with Dwight Yorke and Terry Sheringham restored to the team that overran the Hammers. Yorke responded from his surprise omission with two goals, while Sheringham was given a rare run out. The biggest surprise was Ole Gunner Solskjaer being dropped from the bench after a series of starts.
Cole's absence is unlikely to give Ferguson much of a headache for the Bradford game on Boxing Day, but he will want the 14-goal striker back as soon as possible.