West Ham's medics have been working to find a solution but are beginning to fear more surgery may be the only answer.
West Ham manager Alan Curbishley said: "We have to decide this week where we are going to go with Craig.
"We have to decide whether to continue with the route we are going down which, if it is successful, will result in a shorter route.
"We may have to go down the surgery route which will be a longer one. If that is the case I can't put a time-frame on it."
West Ham believe the problem stemmed from the foot supports Bellamy inserted into his boots during pre-season.