After leading R.B. Stall High School to the South Carolina AAA football championship, Johnson received a basketball scholarship at the College of Charleston, where his older brother Steven was a standout years earlier.
Tras liderar ao Instituto Stall de Carolina do Sur ao campionato AA de fútbol americano, Johnson recibiu unha bolsa de baloncesto do College of Charleston, onde o seu irmán maior Steven sobresaíu anos antes.