Johnson, the No. 6 prospect in the ESPN 100, was named to the SEC's all-rookie team after averaging 11.3 points, 3.5 rebounds and 2.5 assists in 25 minutes per game.
"Since our season ended, I've spent a lot of time thinking, praying and consulting my family and coaches, and I have decided to enter the 2021 NBA draft with representation," Johnson posted on Twitter. "I am forever thankful to God for blessing me with talents, surrounding me with a solid support system and positioning me to take this next big step."
"The NBA has always been my goal, but I never expected it to come this soon," Johnson told ESPN. "I really don't care what number I get drafted at. I just want to go somewhere I fit in that organization. Where I can keep developing and find my niche."
A late bloomer who grew up as a shortstop on the baseball field, Johnson didn't emerge as a top-shelf prospect until the spring and summer prior to his senior year of high school. Strong outings with his AAU team, EAB Tennessee, earned him an invite to USA Basketball, where he established himself as a five-star caliber recruit and potential NBA lottery pick.
After missing most of his senior year of high school with a knee injury, Johnson started his freshman season slowly at Tennessee, coming off the bench for 10 of the first 11 games and playing just 13 minutes in his debut. He improved dramatically as the year moved on, scoring 27 points in a win at Kentucky in February and averaging 17 points per game in his final five contests.
"Once I get comfortable and into a groove I understand the different expectations that are given," Johnson said. "Not starting or not playing as much early in the season didn't bother me because I knew I needed to grow so I took that upon myself to make that change."
Johnson is considered one of the quickest and most explosive players in the college game in terms of his ability to accelerate from a standstill and get off his feet for dunks and blocks. As the season progressed, he started flashing real upside as a ball-handler in pick and roll situations. His ability to play at different speeds, and use or reject a ball-screen, combined with his size, body control, fluidity and creativity as a passer, suggest significant room for growth long-term. Defensively, he proved able to stay in front of guards and wings with his physical tools and aggressive style of play.
"I think NBA teams see a defensive-minded guard who can score at all three levels," Johnson said. "I feel like my 3-point shot is going to improve and keep me on the court in the NBA, along with my versatility on the offensive end."
The NBA announced last week that the draft will be conducted July 29, and has scheduled its draft combine for June 21, featuring competitive 5-on-5 action "subject to public health conditions."
Jonathan Givony is an NBA draft expert and the founder and co-owner of DraftExpress.com, a private scouting and analytics service utilized by NBA, NCAA and international teams.