[1] Johnson was a four-year starter on the varsity football team, playing in the state's largest class (6A).
Johnson received IFCA and AP all-state honors as a junior and a senior, and was the #1 ranked player in the state of Indiana throughout high school.
Johnson was also an all-state track runner while at Brownsburg HS, running the 200, 400, and the 4×400 meter relay.
Johnson was ranked by Rivals.com as the number 18 overall player (across every position) in the nation,[2] and was the 2016 Rivals 5-star challenge quarterback MVP.
Johnson saw limited action against Kent State, Louisville, Wake Forest, Georgia Tech, The Citadel, Miami, and South Carolina.
He threw his first collegiate touchdown to tight end Cannon Smith during Clemson's game against Wake Forest.
In Johnson's third season he battled Ryan Hilinski and Andrew Marty for the starting quarterback position.
In the second game of the season against Indiana State Johnson struggled, throwing for 66 yards, one touchdown and one interception.