L.S.U. severely underachieved. There were injuries and problems with team chemistry issues. The Tigers did not make the N.C.A.A. tournament and elected not to participate in the National Invitation Tournament.

“It was tough, because I’ve never been on a losing team,” Simmons said.

But having ended up on one — and having shouldered the blame for the team’s failures — will help Simmons in his transition to the N.B.A. if he does not get off to a flying start.

“The experience at L.S.U. helped me understand that things are not always going to be perfect,” he said. “I was getting all of that thrown on me, but I had to deal with it, and it came with the territory.”

Simmons signed last March with Klutch Sports. The agency’s highest-profile client is James, the top draft pick at 18 years old in 2003, who Simmons says has become a friend and a mentor. They talk frequently, discussing topics like footwork and how Simmons’s life is about to dramatically change.

“I’ve learned a lot just being around LeBron,” Simmons said. “People say things about him all the time, but he would never say anything back. That’s what I learned from him: Don’t retaliate to articles or pieces or to things that are said about me.”

Simmons is the subject of a documentary, “One and Done,” scheduled to appear on Showtime in October. The film explores Simmons’s journey from Australia to Florida to L.S.U. to the N.B.A. It illustrates the global system that delivers players to college programs in the United States.