SAN DIEGO (AP) ― Tony Gwynn, an eight-time batting champion and an All-Star for almost his entire 20-year Major League Baseball career, 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,” and inducted into the Baseball Hall of Fame in 2007.

“For more than 30 years, Tony Gwynn was a source of universal goodwill in the national pastime, and he will be deeply missed by the many people he touched,” Commissioner Bud Selig said.

Gwynn 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 on Monday at a hospital in suburban Poway.

Gwynn had two operations for cancer in his right cheek from August 2010 to 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.

Gwynn said he believed the cancer was from chewing tobacco.

In a rarity in pro sports, Gwynn spent his entire MLB career with the Padres, choosing to stay rather than leaving for bigger paychecks elsewhere. His terrific hand-eye coordination made him one of the game’s greatest contact hitters. He had 3,141 hits, a career .338 batting average and won eight National League batting titles.

Gwynn played in the Padres’ only two World Series and was a 15-time All-Star, scoring the winning run in the 1994 All-Star Game.

He was hitting .394 when a players strike ended the 1994 season, denying him a shot at becoming the first player to hit .400 since San Diego native Ted Williams hit .406 in 1941.

Gwynn retired after the 2001 season. He and Cal Ripken Jr. ― who spent his entire career with the Baltimore Orioles ― were inducted into the Hall of Fame in the class of 2007.

After spending parts of just two seasons in the minor leagues, he made his big league debut on July 19, 1982. Gwynn had two hits that night, including a double, against the Philadelphia Phillies. After doubling, Pete Rose, who had been trailing the play, said to Gwynn: “Hey, kid, what are you trying to do, catch me in one night?”