Manager Mark McGhee said: "It was a good outcome in the sense we now know why his problems have continued.
"When the first operation was done on his hip in April, it was found there was a lose flap of tissue. Apparently it can re-attach itself, which we hoped would happen.
"But it has not done that so it will have to be removed in an operation.
"The specialist is very confident that after that, the discomfort will go. It will then need another 12 weeks before he can be back in training."