Chicago White Sox pitcher Chris Sale knows the ill effects caused by chewing smokeless tobacco. He particularly knows the effects it probably had on Tony Gwynn, a former San Diego Padres All-Star. Gwynn died in 2014 of salivary gland cancer, and he believed that chewing smokeless tobacco contributed to the disease. RELATED: Tobacco's Effects on Athletic Performance Sale is aware of how tobacco affected Gwynn. At an MLB All-Star Game press conference Monday, he said that he stopped chewing tobacco after Gwynn's death, according to the San Diego Union-Tribune's Kirk Kenney. "I quit that day and haven't touched it since," Sale said. "In a sense, I owe him a huge 'thank you,' not only for myself, but for my family." The MLB All-Star Game will be played at Petco Park in San Diego, California. Sale will be the starting pitcher for the American League. Though cigarettes were proved to cause cancer in the 1950s, plenty of baseball players still used tobacco. Baseball players have used chewing tobacco since the origin of the game, in part because it kept their mouths and mitts moist while they hung out on the dry, dusty infield. Despite a long history of baseball players using chew, the effects are known to be dangerous. Chewing tobacco has been linked to mouth cancer, pancreatic cancer and esophageal cancer. "One of the directs for oral cancer is smokeless tobacco, just what we're talking about here," Dr. Robert Haddad, Disease Center Leader at the Dana-Farber Cancer Institute (Boston), said in 2014 about former Boston Red Sox pitcher Curt Schilling's mouth cancer diagnosis. MLB hasn't banned chewing tobacco, but players aren't allowed to have it in their mouths during on-air interviews or in their back pockets during games.