Realmuto is not in the lineup for Sunday's game against the Braves, according to MLB.com's Joe Frisaro.
Realmuto went just 1-for-12 over his last three games, and the Marlins are playing a day game Sunday following a night game, so manager Don Mattingly decided to give his regular catcher a day off. Jeff Mathis will start behind the plate for the Marlins on Sunday afternoon.