McKenzie is awaiting results of an MRI performed on his right arm Monday, Mandy Bell of MLB.com reports.
McKenzie felt what he thought was normal soreness in his tricep/shoulder area while warming up prior to Sunday's Cactus League start against the Reds. He then alerted the coaching staff when the feeling returned after the first inning, prompting his removal from the game. You'd have to think a stint on the injured list is likely even if the tests come back relatively clean.