(AP) -- Hall of Famer Tony Gwynn has died of cancer at 54.

Gwynn's sweet left-handed swing made him one of San Diego's best-loved athletes. He was nicknamed "Mr. Padre" during his 20-year major league career.

He had been on a medical leave from his job as baseball coach at San Diego State, his alma mater, since late March. Agent John Boggs said Gwynn died Monday in suburban Poway.

Gwynn had two operations for cancer in his right cheek between August 2010 and February 2012. The second surgery was complicated, with surgeons removing a facial nerve because it was intertwined with a tumor inside his right cheek. They grafted a nerve from Gwynn's neck to help him eventually regain facial movement.