Koger played high school football at Whitmer High School in Toledo. He holds the school record with 1,190 career receiving yards on 75 receptions. He finished his career with 16 offensive touchdowns. He recorded 151 tackles, 28 tackles for loss, 16 sacks, two forced fumbles, three fumble recoveries, two interceptions, and one interception return for a touchdown during his career. In his senior year, Koger made 31 receptions for 361 yards, scored five touchdowns, and contributed 48 tackles and seven sacks.
