Koch (5-5) threw three innings and took the loss Thursday, yielding four runs on eight hits and two walks in the 10-3 defeat against Colorado. He struck out two and gave up two home runs.
Koch was called on to spot start after Clay Buchholz (elbow) became a late scratch. Nolan Arenado took him deep in the first inning and Trevor Story hit a two-run blast off him in the third. The 27-year-old will likely stick around in the bullpen down the stretch.