The Reds designated Mariot for assignment Sunday.
Cincinnati removed Mariot from its 40-man roster and 26-man active roster to clear room for Ben Lively (pectoral), who was reinstated from the 15-day injured list ahead of his scheduled start Sunday in Milwaukee. After being called up from Triple-A Louisville on Saturday, Mariot had been available in long relief, but he wasn't summoned from the bullpen in the Reds' 8-5 win over the Brewers.