Arizona Diamondbacks left-hander Jordan Montgomery was activated from the 15-day injured list and will start Tuesday night against the visiting the Kansas City Royals.

Montgomery, 31, progressed enough from right knee inflammation to skip a rehab assignment after three-plus weeks on the IL. He threw a three-inning, 56-pitch simulated game last Thursday.

In a corresponding move, the Diamondbacks optioned right-hander Humberto Castellanos to Triple-A Reno. Castellanos, 26, has a 5.23 ERA in seven relief appearances this season for Arizona.

In his first season with Arizona, Montgomery is 6-5 in 13 starts with a 6.44 ERA over 65 2/3 innings.

Over eight seasons with the New York Yankees (2017-22), St. Louis Cardinals (2022-23), Texas Rangers (2023) and Diamondbacks, he is 44-39 in 154 games (153 starts) with a 3.90 ERA over 820 2/3 innings.