Cashner started Saturday night against Washington.
He was placed on the DL on May 17, retroactive to May 15, with a sore right elbow.
To make room on the roster, left-hander Jason Lane was designated for assignment. He made his major league debut as a pitcher on Tuesday after being selected from Triple-A EL Paso, retiring each of his 10 batters. He appeared in two games, retiring 13 of his 14 batters faced.
Lane played outfield for Houston and the Padres from 2002-2007. He homered for the Astros in the 2005 World Series.