ノースウエストアーカンソー・ナチュラルズ
On March 19, 2018, Buchholz signed a minor league deal with the Kansas City Royals. He recorded a 1-0 record with 9 strikeouts in 3 games for the Double-A Northwest Arkansas Naturals and the Triple-A Omaha Storm Chasers. The Royals released Buchholz on May 1.