He told the Press Association: "The scan shows minor cartilage damage and we will know whether he needs an operation at the end of the week. "He did his cruciate ligaments last season and he has irritated that part of his knee. We are at the moment waiting for it to settle down and then will take it from there. "But, if Mark does need surgery, I don't think that it is going to be a long term thing and certainly nothing like last season."