According to the official web-site it was a simple piece of key-hole surgery which removed some soft tissue. Following the operation Chelsea decided it would be better for him to rehabilitate here in London rather than join the squad with their pre-season training in Italy.
The report stated that Terry has already returned to work on his own at the training ground - you just can't keep a good man down. All the best for a speedy recovery.
stevefurlong@chelsea-mad.co.uk