2003-2005

William Richard Mueller was born on March 17, 1971. 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.

Mueller was born in Maryland Heights, Missouri and attended De Smet Jesuit High School and Southwest Missouri State University. He was drafted by the San Francisco Giants in the 15th round of the 1993 MLB Draft. Mueller made his professional debut with the Giants low A team, the Everett Giants, in 1993 and quickly rose through the Giants farm system, with stops in San Jose, Shreveport, and Phoenix before making his major league debut with the Giants as a pinch hitter on April 18, 1996 against the Chicago Cubs. He played third base for the Giants fairly regularly for five seasons, until he was traded to the Chicago Cubs before the 2001 season for pitcher Tim Worrell. He returned to San Francisco in September 2002 in a trade for pitcher Jeff Verplancke.

Before the 2003 season, Mueller was signed by the Boston Red Sox as a free agent. In his first year in Boston, he won the American League batting title with a .326 average. He also set career highs in the power department that season, belting out 45 doubles and 19 home runs. He had never previously hit more than 10 home runs or 29 doubles in any season.

He contributed nearly half of his career home runs during his three years with the Red Sox. Mueller developed a reputation for consistency throughout the major leagues. In fact, for five of his ten years in the major leagues, his batting average was between .290 and .295. His minor league numbers were very much the same, consistently between .290 and .310.

Mueller joined the Los Angeles Dodgers for the 2006 season and was reunited with Nomar Garciaparra, but played only 32 games before undergoing his third knee surgery, which would prove to be career-ending. On November 17, 2006, the Dodgers announced that Mueller was retiring from baseball and had been hired as a special assistant to the GM. On June 15, 2007, Mueller was named Los Angeles Dodgers interim hitting coach when Eddie Murray was fired. After a month on the job, manager Grady Little announced that the Dodgers would be removing the "interim" tag and that Mueller would remain the teams's hitting coach through the end of the season. After the season, it was announced that Mueller would be giving up his role as hitting coach to return to a front office position. Mueller served as a Special Assistant to General Manager Ned Colletti through the 2012 season, when he left that position to become a full-time scout.

On November 22, 2013, Mueller was named Hitting Coach of the Chicago Cubs under new manager Rick Renteria. On October 7, 2014, he subsequently resigned that position, a week after his assistant, Mike Brumley, was dismissed by the Cubs.