Lynchburg Hillcats
Horst started 2010 with the single-A advanced Lynchburg Hillcats. In 11 relief appearances, he was 0–2 with a 4.30 ERA. He was promoted to Carolina, and in 27 relief appearances, he was 3–2 with a 2.09 ERA. Horst was then promoted to triple-A Louisville and went 1–0 with a 2.51 ERA in 6 appearances (2 starts).