Cain (hamstring) will throw a bullpen Sunday and the Giants will decide afterward whether he will face the Red Sox on Wednesday, Chris Haft of MLB.com reports.

EDGE Analysis

He was blown up for nine earned runs on 10 hits and three walks in four innings in a rehab start Friday, and that was against High-A competition. It seems the Giants need some convincing before returning Cain to the major league rotation. If they are not pleased with how the 31-year-old looks Sunday, they could send Cain for one additional minor league start.