Johnson matriculated at New Mexico Junior College before moving on to Cameron University, and finally Southern University, at which in his senior season in 1988 he led NCAA Division I with 13.3 assists per game, an all-time record.
Johnson se matriculou no New Mexico Junior College antes de irse á Cameron University, e finalmente á Southern University, na cal no seu ano sénior en 1988 liderou a NCAA con 13.3 asistencias por partido, récord de todos os tempos que aínda conserva.