The Giants designated Howard for assignment Sunday, Shayna Rubin of the San Francisco Chronicle reports.
The right-hander surrendered six runs over 2.2 innings Saturday against the Dodgers and has now lost his place on the Giants' 26-man active roster and 40-man roster. Howard has struggled to a 5.63 ERA and 21:11 K:BB over 24 frames in the big leagues this season.