Graterol (shoulder) issued one walk and struck out one batter in a scoreless inning for Triple-A Oklahoma City on Friday.
Graterol's first game action in just over a month went well, as he faced the minimum on 14 pitches. He walked the first batter he saw before inducing a double play and finishing the frame with a strikeout. Graterol will likely need a few more rehab appearances before returning to the big club.