Muller (0-1) took the loss in an extra-innings defeat at the hands of the Rockies on Wednesday, allowing two runs (one earned) on two hits over one inning.
Muller was entrusted with preserving a 2-2 tie when he entered in the 12th inning, but he faltered almost immediately by giving up a go-ahead two-run home run to Ryan McMahon with designated runner Jake Cave aboard. Oakland would halve its two-run deficit in the home half of the frame but fall short of knotting the score back up, saddling Muller with his first loss. The southpaw sports a respectable 3.94 ERA and 1.18 WHIP, but he's allowed at least one run in nine of his 12 appearances.