D'Arnaud (shoulder) will undergo further medical testing Tuesday, Adam Rubin of ESPN reports.
D'Arnaud first started to feel discomfort in his right shoulder Monday after a throw to second. His situation should be cleared up following the release of his medical results Tuesday, although early indications suggest he'll have to miss time since Triple-A catcher Rene Rivera was pulled early from Monday's game after just one at-bat, likely indicating a call-up. That said, Kevin Plawecki will serve as the Mets' primary catcher in the potential absence of d'Arnaud.