Buller is attempting to revive his career from two arm surgeries after pitching professionally in the Arizona Diamondbacks organization, the Gateway Grizzlies (Frontier League) and playing four years at first base for Division I Houston Baptist, where he set a school record by hitting 16 home runs as a junior in 2011. Drafted in 35th round by the Diamondbacks in 2012, he appeared in six games for Missoula (Pioneer League) as a first-year pro in 2013, striking out 11 in 11 1/3 innings, allowing only nine hits, and three walks. Still, he hit two batters with pitches and threw five wild pitches. In Gateway, he appeared in five games and allowed only three hits in 7 1/3 innings in 2015, but suffered through a 9-8 strikeouts to walks ratio. Throws fastball, slider, and change-up.