As a senior at Norfolk High School, McGill was responsible for causing seven turnovers, including four interceptions. McGill also produced 29 tackles and one quarterback sack, while leading his team to a 7-4 record and an appearance in the quarterfinals of the Nebraska state high school football championships. On offense, McGill rushed for 514 yards and four touchdowns at fullback, while averaging five yards per carry. He also caught 15 passes for 215 yards and a touchdown.
McGill received interest from several Division II schools before deciding to walk on at NU.