Gerrion Grim redshirted in his first season at the University of Missouri. As a senior, Grim compiled a .354 batting average, with five home runs and 56 RBI. He also posted a 17-11 record on the mound during his four year career at Fort Zumwalt South in St. Charles, Missouri. In 2012, Grim was the St. Charles Male Athlete of the Year and First Team All-State selection. Grim owns the school career strikeout record with 211.