Somsen is likely to be assigned to Triple-A Oklahoma City. In a combined 25 innings with Triple-A Louisville and Scranton Wilkes-Barre this year, Somsen struck out 29 and yielded a 1.44 ERA. He was originally drafted in the 22nd round of the '13 Draft out of South Dakota State.
Tsao had been on the 15-day DL since May 23 with a right triceps strain. In two appearances with the Dodgers this season, he allowed a hit and three walks.
Jack Baer is a reporter for MLB.com based in Los Angeles. This story was not subject to the approval of Major League Baseball or its clubs.