The Rockies selected Adams' contract from Triple-A Albuquerque, and he will start Tuesday's game against the Nationals.
It will be the major-league debut for the 26-year-old, who has a 3.67 ERA, 1.20 WHIP and 49:20 K:BB across 49 innings at the Triple-A level this year. Adams was acquired from the White Sox in the Brenton Doyle trade in early August and could get at least a couple turns through the rotation after Kyle Freeland (neck) was placed on the injured list Monday.