Bierman, taken in the 10th round of the 2012 First-Year Player Draft, went 6-5 with a 2.55 ERA over 18 games (14 starts) between Class A Bowling Green and Class A Advanced Charlotte in 2013.
Klein, a 32nd-round pick in 2012, batted .246 with 14 runs and 15 RBIs between Class A Hudson Valley, Bowling Green and Charlotte.
The Rays acquired Crain from Chicago on July 29. The right-hander had a strained right shoulder when the Rays acquired him, and he did not pitch. He is eligible for free agency.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.