The person spoke on condition of anonymity Thursday because the team did not make that detail public.
Dr. Bryan Kelly of the Hospital for Special Surgery, who operated on A-Rod on Wednesday, said last week the extent of cartilage damage was a concern and could not be determined before the operation.
Kelly repaired a torn labrum and reshaped the bone to alleviate impingement. The Yankees said Wednesday the operation "went as planned and without complication."
New York said recovery time is six months, a timetable that projects Rodriguez to return after the All-Star break.