On April 20, 2021, Kitchen signed a minor league contract with the Colorado Rockies organization.[10] He pitched 19 games for the Single–A Fresno Grizzlies, compiling a 4.97 ERA with 38 strikeouts across 50+2⁄3 innings.[11] Kitchen started 2022 with the High–A Spokane Indians and was promoted to the Double–A Hartford Yard Goats at the end of July. In 36 total games, he posted a cumulative 5–2 record and 3.32 ERA with 71 strikeouts across 81+1⁄3 innings pitched. Kitchen spent the 2023 season back with Hartford, also making two appearances for the Triple–A Albuquerque Isotopes. In 43 games out of the bullpen for Hartford, he recorded a 3.62 ERA with 54 strikeouts and 3 saves across 59+2⁄3 innings of work.[12][13]
Kitchen began 2024 with Hartford and was promoted to Albuquerque after 5 games. In 18 games for the Isotopes, Kitchen registered a 3.65 ERA with 18 strikeouts.[14]
On June 25, 2024, Kitchen was claimed off waivers by the Miami Marlins[17] and optioned to the Triple–A Jacksonville Jumbo Shrimp.[18] The Marlins promoted Kitchen to the major leagues on July 26,[19] but he was optioned to back to Jacksonville the next day, without pitching for Miami.[20] He was promoted once more on July 30.[21] He made his major league debut that day, allowing 3 runs in 2 innings in a loss to the Tampa Bay Rays.[22] Kitchen made four appearances for the Marlins, with a 14.14 ERA, one loss, and four strikeouts over seven innings.[23] He was designated for assignment by Miami on September 7.[24]
Seattle Mariners
On September 9, 2024, Kitchen was claimed off waivers by the Seattle Mariners.[25][26] He was optioned to the Triple-A Tacoma Rainiers,[18] where he pitched four times, posting an unsightly 14.73 ERA in 3+2⁄3 innings. His combined pitching line for three Triple-A teams in 2024 was a 6–1 record with a 4.33 ERA and 27 strikeouts in 43+2⁄3 innings.[12]