When Leach clears waivers, he is expected to be sold to Yokohama of the Japan League, according to a baseball source.
Leach, 28, pitched in 38 games in relief for the Dodgers in 2009, but he regressed in '10 and never reached the Major Leagues, splitting the season between relieving at Triple-A and starting at Double-A. He was 3-2 with a 6.35 ERA at Albuquerque and 7-3 with a 4.57 ERA at Chattanooga.
Leach was a sixth-round Draft pick in 2005 out of Delta State University, missing the 2004 season with Tommy John surgery.
Guerrier was signed last week to a three-year, $12 million contract to bolster the Dodgers' bullpen.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.