Rodriguez (knee) threw a bullpen session Tuesday, Evan Drellich of the Boston Herald reports.
Rodriguez has already embarked on a rehab stint and is scheduled to start Friday with Triple-A Pawtucket, but it appears as though a return is imminent shortly after that. Despite making 21 starts with Boston last season, it remains to be seen though if he'll head to the majors or stay at the Triple-A level when healthy.