"I wouldn't rule that out," said Red Sox manager John Farrell.
The next step will be another bullpen session before Wednesday's game against the Tigers. By the weekend, Kimbrel could go on a Minor League rehab assignment which could last as little as one game depending on how he feels.
"He was aggressive for the 25 pitches he threw [Monday]," said Farrell. "Both his fastball and his curveball. It didn't look like, to the naked eye, that he was favoring anything. We had him throw on the mound on the main mound so we could get the pitch tracker on him and just make sure his release point, arm angle, those types of things, are consistent with game activity.