Luke Prosser has undergone further surgery as he continues his quest to regain full fitness.
The U's skipper suffered a serious knee injury last season, and was hoping to be fit for the upcoming campaign.
He worked through the summer, but as physio Tony Flynn explained to cu-fc.com, he has needed another operation.
Flynn said: "With one particular movement, Luke was feeling a bit of pain and discomfort that we couldn't get rid of, so we sent him to see the specialist.
"On going in, there was some damage in the kneecap and a bit of bone had to be shaved off.
"The specialist reassured us that the original operation was successful and there were no problems with that, but Luke will still be out of action for the next six to eight weeks."