On March 3, 2021, Motter signed a minor-league contract with the Colorado Rockies. After playing in 67 games for the Triple-A Albuquerque Isotopes, hitting .335 with 24 home runs and 57 RBIs, Motter's contract was selected by the Rockies on August 10, 2021. In 13 games for the Rockies, Motter struggled to a .150 average (3-for-20) without a home run or RBI. On August 30, 2021, Motter was designated for assignment by the Rockies.
