After graduating from high school, Vlasic played college football at the University of Iowa. For four years, he served as a backup to Chuck Long, now a member of the College Football Hall of Fame. During his junior year, as the backup quarterback, he also served as the holder for field goal kicks. After placekicker Rob Houghtlin won a 12-10 game against the University of Michigan thanks to a last second field goal, a mob tore down the goalpost, which injured four fans including Vlasic, who was at the bottom of a pile of fans.