Johnson is a returning Honker. As a junior for the Fighting Illini in 2012, Johnson was second on the pitching staff with 7 wins and recorded the second highest ERA of the Illinois starters at 3.97. In 2011 for Rochester, the Midlothian, IL native pitched in 9 games and finished with a 3-2 record and a 6.43 ERA. Johnson only surrendered 2 home runs in 84 innings of work. In high school, Johnson was listed as the No. 13 recruit in the state of Illinois by Prep Baseball Report.