TUCSON, Ariz. — Lute Olson's doctor says the former Arizona basketball coach had a stroke within the last year and he advised him to retire.

The 74-year-old Olson suddenly announced his retirement last week, two days after he appeared at the Wildcats' media day. He said at the time he was "energized" and looking forward to his 25th season with Arizona.

Dr. Steven Knope said Tuesday an MRI confirmed the stroke, which left Olson with severe depression and impaired judgment.

Olson took a leave of absence last season for what he later termed a "medical condition that was not life-threatening."