Former prep star at nearby Bellefontaine High School, recently completed a collegiate playing career at the University of Akron and The Ohio State University. Mosbarger spent three seasons playing at Akron before the baseball program was terminated in 2015. He started 101 games over the course of his career as a two-way player at outfield and pitcher. He hit for a .247 average at the plate with four home runs, 24 doubles, and four triples, while recording 31.2 combined innings with a 1-0 record on the mound for the Zips. Mosbarger then transferred to The Ohio State University for his final year of eligibility in 2015-16. He made 14 appearances in the field, including eight starts for a Buckeye squad that went 44-20-1 and captured the 2016 Big 10 Tournament title. OSU went to the Louisville Regional that year, where Mosbarger went 2 for 2 with three RBI and a home run against the second-ranked host Cardinals. He also made an impact on the bump for OSU, registering 32.2 innings and a 2-0 record in five starts, with one of those starts being against Michigan State in the semi-finals of the Big Ten Tournament.