Ben Simmons underwent what was determined to be a successful back surgery in Los Angeles on Thursday. The Brooklyn Nets are hoping that he is fully recovered before the start of training camp this fall.

Simmons will need about three weeks for an “initial recovery period,” the Nets said, before he can start his rehabilitation program. The procedure Simmons had was called a microdiscectomy, in which a small fragment of a herniated disc is removed to relieve pressure on the spinal column.

Training camp will start in late September.

Simmons last played a game on June 20, 2021. He missed this entire season — some with Philadelphia before being traded to the Nets in the move that sent James Harden to the 76ers — for a variety of reasons, including mental health concerns before the trade and then what were originally called back spasms after the trade.

The hope is the surgery will allow Simmons to get back on the court, play without pain and become another key piece of a title-contending group led by Kevin Durant and Kyrie Irving that Brooklyn envisions. Working through the mental issues that Simmons is dealing with, Nets coach Steve Nash said toward the end of Brooklyn’s season, will remain a top priority for the team as well going forward.

“There is a mental component with everything,” Nash said late last month. “I think Ben has addressed that there is a mental component with what he’s going through. But how much and where he’s at with that is not for me to speak about. But as far as an organization, we’re really pushing to support Ben in any way we can to help him improve physically and get back on the court.”

This was the second full season that Simmons has missed in the past six years. He was picked No. 1 in the 2016 NBA draft but didn’t debut that season because of foot issues. He was rookie of the year in the following season, 2017-18, and was picked for the NBA All-Star games in 2019, 2020 and 2021.

Simmons has three years and nearly $114 million remaining on his contract.