Moustakas will sit against lefty Kyle Muller in Atlanta on Thursday.
Moustakas and Eugenio Suarez are expected to platoon at third base down the stretch, a plan the Reds have largely stuck to since Moustakas returned from a heel injury in early August. He's started against all but one righty over that stretch but hasn't started against a single southpaw. Suarez will handle the hot corner in his absence.