Morse suffered a setback Monday while playing for Class A Hagerstown, leaving the game in the seventh inning against Lexington because of a strained lat (back) muscle.
Morse can swing the bat without any problems, but he continues to feel discomfort while throwing the baseball. In fact, Morse had problems throwing the ball back to Hagerstown shortstop Jason Martinson in the game.
"Last I heard, we were sending the test to Andrews to see what his thought process is," manager Davey Johnson said Wednesday. "We should hear something today on Michael Morse."