Johnson (0-1) was charged with the loss Tuesday against the Cardinals after he allowed three runs on three hits and one walk over two-thirds of an inning.
Johnson entered for the ninth inning with the game tied 6-6, only to surrender a home run to Nolan Gorman on his first pitch, and St. Louis then struck for two more runs. The right-hander has served as Colorado's closer to begin the season with Daniel Bard on the injured list due to anxiety, and he has three saves with four runs allowed and a 7:4 K:BB across 4.2 innings.