O'Sullivan (knee) will make a rehab start with Triple-A Pawtucket on Thursday, Ryan Hannable of WEEI reports.

EDGE Analysis

While his rehab seems to be progressing well, with the trades the Red Sox have made at the deadline, it seems O'Sullivan likely won't get a starting spot once he's back. Depending on how well he pitches from the bullpen, it will determine his value moving forward.