Renfroe (hamstring) will begin a rehab assignment with Double-A Northwest Arkansas on Wednesday.
Renfroe went through a full workout Tuesday and will now test himself in a game setting. The 32-year-old could require just one rehab contest, as he is poised to rejoin the Royals' active roster this weekend if all goes well. Renfroe has been shelved since late August with a right hamstring strain.