Johnson has been suspended for the 2013-14 season, and fellow starter Kevin Bright has decided to sign with a pro team in his native Germany.
Johnson averaged 13.5 points, 3.6 assists and 3.5 rebounds this past season while Bright averaged 6.9 points and 5.5 boards per contest. Vanderbilt finished 16-17 overall last season and was 8-10 in SEC play after losing its top three players -- John Jenkins, Jeff Taylor and Festus Ezeli.
Johnson wrote a letter to the Vanderbilt fan base Monday acknowledging that he has been suspended for a "violation" that took place near the end of this past academic year.
"As we get closer to starting the new school year, I feel it is my responsibility to inform everyone of some disappointing news. I have been suspended as a student from Vanderbilt University for one year for a mistake I made, the result of using some very poor judgement," Johnson's statement said. "That also means I will not be on the basketball team this upcoming season.
"It hurts me when I realize the consequences of my action, which happened near the end of the last school year. It was a violation of the good conduct expected of all Vanderbilt students. I take full responsibility and now must begin working to regain the trust and respect of my school, the student body, our fans and especially my coaches and friends on the team. I understand this will take time."
Bright was a promising freshman last season and started 29 games. The native of Mannheim, Germany, inked a pro contract with the Fraport Skyliners in Frankfort because of personal reasons. His mother is dealing with health issues, and Bright returned last week to help take care of her.
"He decided that the best thing for he and his family was to sign a professional contract so he could be near her," Vanderbilt coach Kevin Stallings said. "While the timing of this is very unfortunate, we understand Kevin's desire to be present for his family in this time of need."