The team said Thursday the procedure of the lumbar spine was performed by Dr. Andrew Dossett at the Carrell Clinic.
Porter was taken by Denver with the 14th overall pick in the June draft. He was considered a top-five selection before a back injury that required surgery limited him to three games at Missouri in 2017-18.
The 6-foot-10 Porter was hampered by back and hip soreness during pre-draft workouts. But the Nuggets felt his talent was work the risk, with Nuggets president of basketball operations Tim Connelly saying at the time: "You have to take a swing at guys like that."