Theres not a ton of areas to assess Johnson in terms of areas to improve since we haven’t saw much of him at the NFL level. He likely still possesses some of the weaknesses he had in college, which is why he was a sixth-round pick.
Although out of Johnson’s control, his athleticism is what will always hamper his performance in his NFL career. His aggressive play style boded well for him in college, but with bigger and faster players in the NFL he could run into some problems because of his stature.
Joe Marino states his concerns with the young safety, and they line up with most of the concerns that many have with him.
"There is so much to like about the way Johnson plays forward by aggressively attacking the football, playing thought contact and finishing. With that said, his body composition doesn’t mesh well with his best qualities as a football player. While the NFL likes physical and aggressive safeties, it covets those that are sound in coverage and can make game-changing plays on the ball – that’s where Johnson is lacking. His coverage instincts and ball skills are below average, especially for a player with his experience. Johnson should be a special teams standout that offers upside in sub-packages on defense but there is considerable growth needed for him to be viewed as a starter."
Despite having great turnover numbers in college, Johnson still lacks in ball skills, sometimes he is slow to react to the ball in the air, and his lack of length makes it tougher for him to come up with the ball.
When Johnson is forced to play man coverage he can struggle, he is regularly tight in his hips and struggles to remain with deep receivers approach him.
The productive safety will struggle to cover the deep parts of the field, and could become a bit of a liability in Cover 2 looks, with his range being limited.
Most of the problems with Johnson comes down to his lack of athleticism, if he can become excellent in his football IQ, he can become the best version of himself and could be a solid starter despite his deficiencies. Sean McDermott regularly gets the best out of his defensive players, especially in the secondary so expect Johnson to play up to or past his potential.