Michael Porter Jr., the 14th pick in the 2018 NBA draft, has undergone surgery of the lumbar spine, the Denver Nuggets announced Thursday.

The Nuggets said there is no timetable for Porter's return to basketball participation.

The procedure, performed by Dr. Andrew Dossett at The Carrell Clinic in Dallas, is the second for Porter in less than a year. The 6-foot-10 forward played in just three games last season after suffering a back injury just two minutes into his Missouri debut. He had a microdiskectomy of his L3-L4 spinal disks in November 2017 and was expected to miss the remainder of the season. Porter returned late in the season to play a pair of games for the Tigers -- one each in the SEC and NCAA tournaments.

Porter's father, Missouri assistant coach Michael Porter Sr., told The Kansas City Star on Thursday that Porter could be ready for the start of the season.

"Mike's feeling great," Porter Sr. told the newspaper. "The doctors got more insight into what was going on. Just cleaned up a bit of a herniation that was pressing on a nerve. ... The initial prognosis, it sounded like he could be ready at the start of the season. It's a good deal all the way around."

Porter, who was projected to be a high lottery pick, also dealt with a hip strain and back spasms leading up to the draft, which likely contributed to his slide to the Nuggets at No. 14.