For the 1940s Major League Baseball player, see Bill Mueller (outfielder).William Richard Mueller (/?m?l?r/; born March 17, 1971) is an American retired professional baseball third baseman and the current hitting coach of the Chicago Cubs. Mueller's playing career was spent with the San Francisco Giants (1996–2000, 2002), Chicago Cubs (2001–2002), Boston Red Sox (2003–2005), and Los Angeles Dodgers (2006). He won the American League batting title in 2003, and helped the Red Sox win the 2004 World Series. He was a switch hitter and threw right-handed.