Graterol was removed from Tuesday's game against the Phillies with a right hamstring strain.
Graterol was grabbing at his right hamstring and had to be helped off the field by a trainer after throwing just eight pitches in the sixth inning of Tuesday's contest. The 25-year-old had been making his season debut after sitting out the first four months of the season due to a shoulder injury, and he'll now presumably undergo testing to determine how much more time -- if any -- he'll have to miss.