He's young still, even if he did appear in 11 games last season, with three starts at defensive end for a team that finished 2-10 overall.
His ideal weight is 250-255.
However, despite his youth and thin resume, the former four-star prospect and U.S. Army All-American has certainly left an impression on first-year head coach Hugh Freeze.
"I think he's our best player," Freeze said of Johnson. "We need to keep him healthy. I expect him to be a major factor in our pass rush schemes."
Johnson was caught off guard Monday when made aware of Freeze's comments. Despite its depth issues, Ole Miss has some notable names, from junior safety Charles Sawyer to wide receiver Donte Moncrief.
Johnson attributed the praise of his head coach to the hard work he's put in.
Primarily a linebacker in high school, Johnson was switched to defensive end late last season. But he quickly transitioned to the position, totaling 32 tackles, including 4.0 tackles for loss and one sack.
"I'm pretty comfortable at this point," Johnson said. "It's just a matter of can't lose focus of the task. You got to go out and get better every day. (Defensive line) Coach (Chris Kiffin) always talks about adding tools to your toolbox. The more tools you have in your toolbox, the better chance you have of getting to the passer."
Freeze would prefer Johnson add some weight to his toolbox.
Listed at 6-foot-3, 233 pounds, Johnson said he's nearing 240 with the season-opening game vs. Central Arkansas set for today at 6 p.m. Before he graduates, however, he'd like to add more.
"Wish he were a little heavier," Freeze said. "We've got to hopefully get him a little bigger and be smart when we use him. But couldn't be more pleased with the way he's bought in and the way he's practiced up to this point."
"I've actually gained a few pounds," Johnson said, adding that he tries to eat five to six meals a day. "It's just more about the things they've asked me to do and the way they want me to play requires me to gain a little bit a weight. But I'm sure that won't be a problem."
The Ole Miss defense finished near the bottom of the Southeastern Conference in most statistical categories last season, with an inability to rush the passer a big reason why.
Johnson and Co. are tasked with turning the tide, and the freedom of the Rebels' newly-installed 4-2-5 defense could help.
"I think now we're getting to the point where we can play fast," Johnson said. "Everybody's starting to get the concept of the defense and everybody's starting to understand the scheme, so it's making things go a lot better. Right now, we're looking pretty good."
Two newcomers in particular have looked good to Johnson.
Freshman defensive tackle Issac Gross, who weighs in at 260 pounds, only needed a month of practices to emerge as a starter at defensive tackle. Then there's Channing Ward, cleared by the NCAA two weeks into fall camp.
Gross and Ward, along with Johnson and veterans E.J. Epperson, Jason Jones, Cameron Whigham, Bryon Bennett and others, are being called upon to produce in 2012.
"Those guys have come on way faster than I event thought that they would," Johnson said of Gross and Ward. "They're out early before practice, getting extra reps. During practice, communicating with the coaches and the people that are trying to help us rush the passer.
"That was Coach Kiffin's emphasis when he first got here, was to rush the passer. We have to get after the quarterback. That's what they've taught us to do, and that's what we're going to try to do every Saturday."
The first test is Central Arkansas.
Johnson said with school in session, he's had more time to watch film of the Bears, a spread team.
"They do a lot of things that can hurt us if we're not careful, if we're not playing assignment-sound football," Johnson said. "You can't sleep on anybody. We've just got to come out focused and be ready to play."
His ideal weight is 250-255.