Gallen (2-4) took the loss Saturday, allowing two runs on six hits and two walks over five innings while striking out eight as the Diamondbacks were blanked 4-0 by the Brewers.
Eric Thames and Trent Grisham hit back-to-back homers off the rookie right-hander in the fourth inning, and with the Arizona offense getting nothing done, Gallen was stuck with his first loss as a Diamondback. He'll carry a 2.56 ERA and 68:30 K:BB through 56.1 innings into his next start Friday, at home against the Dodgers.