McKenzie underwent an MRI on Monday that revealed a right teres major muscle strain. He'll be shut down from throwing for two weeks and could remain sidelined for up to eight weeks.
The MRI didn't bring the favorable news the Guardians were hoping for with Opening Day only a few days away, but they'll undoubtedly elect to play it safe with one of the top arms in their rotation. A more precise target date for McKenzie's return as well as a plan for his rehab program could come into focus once he's re-evaluated in the second week of April.