Polanco underwent an MRI on Thursday and has been diagnosed with Achilles bursitis, Anthony DiComo of MLB.com reports.
It's good news for Polanco, as he will not require a stint on the injured list and is expected to be available off the bench Friday against the Athletics. With Polanco getting the night off Friday, Ronny Mauricio is starting at third base, and Bo Bichette will serve as the designated hitter. Through his first 45 plate appearances with the Mets, Polanco is slashing .200/.289/.275 with three doubles, one RBI, two runs scored and a 5:6 BB:K.