KANSAS CITY -- Right-hander Kyle Zimmer, the Royals' No. 2 prospect according to MLBPipeline.com, left a start on Tuesday night at Double-A Northwest Arkansas after throwing 22 pitches in one inning.
The Royals have not attached any specific injury for Zimmer's departure and simply are labeling him "day to day."
Royals general manager Dayton Moore indicated he wasn't sure as of Wednesday morning whether Zimmer had been evaluated medically. Zimmer was scheduled to throw three to four innings on Tuesday.
Zimmer has battled arm and shoulder issues during his Minor League career since the Royals selected him in the first round of the 2012 Draft.