Graterol (forearm) threw a 30-pitch bullpen session Friday and will do so again Tuesday, Bill Plunkett of The Orange County Register reports.
The right-hander tossed a 20-pitch session early last week, so he appears to be making steady progress toward a return. Graterol has been out since late April after experiencing right forearm tightness. If his bullpen goes well Tuesday, the fireballing reliever could start a rehab assignment soon thereafter, per Plunkett.