In 21 plate appearances for St. Louis this season -- his first in the Major Leagues -- the 24-year-old Komatsu had four hits and a pair of walks.
In two Double-A stops last season, Komatsu batted .277 with seven homers, 24 doubles and 21 stolen bases. He was originally selected by the Brewers in the eighth round of the 2008 First-Year Player Draft, but was traded to Washington at the Trade Deadline last season.
Thomas was claimed off waivers from Detroit on April 14 and appeared in 12 games for the Twins, batting .143 with a homer and four RBIs. He struck out 16 times in his 28 at-bats.
In addition to the Thomas and Komatsu moves, infielder Sean Burroughs, who was 2-for-17 this year, cleared waivers and was outrighted to Triple-A Rochester.
AJ Cassavell is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.