Koch went unclaimed off waivers Wednesday and was sent outright to Triple-A Albuquerque.
Koch split time between Colorado and Albuquerque in 2023, turning in better numbers at the major-league level with a 5.12 ERA and 1.29 WHIP across 38.2 innings. Koch will have the right to elect free agency during the offseason, and he figures to at least draw a minor-league deal for 2024 if he choses to leave the Rockies.