Kimbrel (knee) will begin a rehabilitation assignment Saturday for Triple-A Pawtucket, Julian Benbow of the Boston Globe reports.
The Red Sox are waiting to see how Kimbrel responds from Wednesday's bullpen session, his second of the week, before committing the injured closer to Pawtucket. Manager John Farrell said the rehab stint could be a short one, and KImbrel could rejoin the Red Sox as early as next week during their 11-game road trip.