Joseph Johnson was a three-year varsity player for Gretna High School, playing 35 games for head coach Dave Shrader. The 6-3, 220-pound linebacker recorded 288 total tackles during his prep career, including 102 solo stops. As a senior, he had three sacks for a combined loss of 25 yards, three interceptions and two fumble recoveries – one which he returned for a touchdown. Johnson was named to the Lincoln Journal Star Super State Team in 2017. He also plays basketball for Gretna.