Team officials said Tuesday that Simmons went through the procedure in New York.
There is no timetable yet for his return.
Sixers coach Brett Brown said he talked with Simmons about two hours before his team's preseason opener against Boston.
"We talked a little bit about what the plan is now," Brown said. "I'm excited. In a very sort of twisted way, once you admit and you sort of come to grips with what has happened, I'm excited to dig into a different part of his development."
Brown noted he's no stranger to this sort of speed bump in developing his young players.
"I think go back to Year 1, you're with Nerlens [Noel], and then you go to Joel [Embiid], and then you go to Jahlil [Okafor], and now I'm with Ben," Brown said. "And it's holistic. You can sit in a room and you can look at edits of some of the great point guards, some of the great do-all-type players, multi-purpose-type players, that we all sort of look at Ben as growing into. So there's a classroom aspect of it.
"There is an opportunity to break down his shot part of it," Brown added. "There is an amazing reality that when we are now in this new practice facility that is a basketball health club, you can just move him within a tight proximity over to the sports science side of things: the wet area, the rehab, prehab, massage therapy area. Then he can walk a few feet on the court and work on his shot. Then he can go a few feet over and go into a beautiful room to watch video on a very professional large screen. We did not have any of that where we were previously with those other three high draft pick injuries. And so the holistic approach is what I'm talking about with Ben, and I look forward to sort of leading that charge."
Simmons was injured Friday during the final training camp scrimmage at Stockton University in New Jersey. The Sixers said Simmons rolled an ankle; X-rays and an MRI revealed a fractured fifth metatarsal bone.
The Australian forward played at LSU last season. He missed time early during his stay with the Tigers while waiting for an ankle injury to heal, and Simmons also left an NBA Summer League contest in July after suffering cramps in both legs.