Johnson played three years at Louisville and put up 43 tackles, four for a loss, two interceptions, 13 pass deflections, a fumble recovery, and three forced fumbles.[4] Johnson's best season for Louisville came in 2019 where he put up 27 tackles, two going for a loss, an interception, six pass deflections, a fumble recovery, and three forced fumbles.[5] After the conclusion of the 2020 season, Johnson announced that he would be transferring to the University of Virginia for his remaining years.[6][7] In his first year with Virginia he put up 44 tackles, two going for a loss, three interceptions and five pass deflections.[8] Johnson had a breakout year in 2022, posting 51 tackles, three being for a loss, two interceptions, and 12 pass deflections.[9] For his stellar performance on the year he was named First team All-Atlantic Coast Conference.[10] After the end of the 2022 season Johnson declared for the NFL draft.[11] He would also earn an invite to the 2023 Senior Bowl.[12] In the senior bowl Johnson had an amazing game, intercepting a pass by Malik Cunningham and returning it for a touchdown.[13][14]
On October 17, 2023, Johnson was signed to the Green Bay Packers practice squad.[21] He was released on November 28 and re-signed to the practice squad on January 2, 2024.[22][23] He signed a reserve/future contract on January 22, 2024.[24] He was released on May 6, 2024.[25]