Eflin (knee) will begin a rehab assignment at Clearwater on Thursday, MLB.com's Todd Zolecki reports.
Eflin underwent knee surgery this offseason, and most of the spring has been dedicated to rehabbing the ailment. He's progressed from bullpen sessions to simulated games, and now finally appears ready for live action. Once ready, the right-hander is projected to join the rotation at Triple-A Lehigh Valley.