Thompson was drafted by the St. Louis Cardinals in the 16th round of the 2002 amateur draft out of Dixie State College of Utah. He holds the AA single-season scoreless innings streak. He made his major league debut on May 8, 2005. In his rookie season, he had 40 appearances and a 2.95 ERA in 55 innings pitched. On July 3, 2006, Thompson was sent down to the Cardinals' AAA affiliate, the Memphis Redbirds.
