As a senior in 2017, he totaled three interceptions, nine pass break-ups, and 49 tackles, earning the Big Sky Defensive Player of the Year award[3] and consensus First Time All-American honors.

[10] As a rookie, Johnson recorded his first career sack and forced fumble against the Green Bay Packers in week 4, taking down quarterback Aaron Rodgers with a strip-sack.

[13] In Week 14 of the 2020 season against the Pittsburgh Steelers on Sunday Night Football, Johnson intercepted a pass thrown by Ben Roethlisberger and returned it for a 51-yard touchdown during the 26–15 win.

[14] In the Divisional Round of the 2020 playoffs against the Baltimore Ravens, Johnson intercepted a pass thrown by Lamar Jackson in the Bills' endzone and returned it for a 101-yard pick six during the 17–3 win.

[18] Johnson suffered a forearm injury just a few plays into the 2024 season opener after colliding with teammate Taylor Rapp on a tackle attempt.