The Giants optioned Lonsway to Triple-A Sacramento following Game 1 of Saturday's doubleheader against the Diamondbacks.
Lonsway was promoted from the minors ahead of Saturday's doubleheader and officially made his major-league debut in Game 1, when he allowed three runs (two earned) on five hits while striking out two batters across two frames. He'll head back down to Triple-A in order to make room on the active roster for Yunior Marte, who will start in the nightcap.