Keller (3-8) was tagged with the loss Sunday against the Phillies after allowing four runs on eight hits while fanning two across five innings.
Keller posted a 3.21 ERA across 28 innings at Triple-A, but he can't seem to break through at the big-league level. He sits with a 7.05 ERA across 13 starts (52.1 innings) and has been particularly brutal of late, giving up 10 earned runs with seven strikeouts and six walks over his last 9.2 innings (three starts).