[1] "An unheralded prep player from New Jersey who spent as much time on the basketball court as the football field," Johnson redshirted his freshman season, but entered training camp in 2013 eager to make an impact on the defensive line, establishing himself as a candidate to start opposite DaQuan Jones, Penn State's star defensive tackle that season.

[4] The Patriot News columnist Bob Flounders rated him among the most important components to Penn State's team entering the 2014 season.

[5] Early in the season, he did not compile many defensive statistics, but Penn State coach James Franklin commented, "[Johnson is] probably the most athletic 315-pound guy I've been around.

The thing I like the most about him is every time I see him when he walks in the building or he's out at practice, he's got a huge smile on his face," going onto note that he has the ability to "wreck" an opponent's game.

Four games into Penn State's season, they had the best rush defense in the country, which Franklin attributed largely to the efforts of Johnson.

Scouts and representatives from 31 NFL teams attended Penn State's pro day to evaluate Johnson, Christian Hackenberg, Jordan Lucas, Anthony Zettel, Carl Nassib, and eight other prospects.

During a Week 11 matchup against the Indianapolis Colts, he made two solo tackles and was credited with half a sack on Andrew Luck, as the Titans lost 24–17.

[21] In Week 4 against the Los Angeles Rams, Johnson recorded his first sack and forced fumble as a Giant during the 17–9 loss.

[28] Johnson recorded his first NFL interception on October 27, 2024, catching a deflected Geno Smith of the Seattle Seahawks pass.