Joel Embiid had surgery to repair the meniscus tear in his left knee on March 24. At the time, the 76ers said it was a minor procedure.
However, he has yet to be cleared for five-on-five scrimmages with training camp starting on Tuesday.
"To be able to specifically tell you what I'm about to get out of him next week, I'm not able to do that now," Sixers coach Brett Brown said Wednesday.
Embiid has been working out with the Sixers' strength and conditioning coaches. Brown said he's getting in better shape.
"But in regards to playing five-on-five basketball and when that can actually happen, right now we can't give you a direct answer," he said.
Sixers president Bryan Colangelo said it's early in the process to determine where Embiid is in his progression to get back to playing.
He said the team is putting the 23-year-old center in a "very hyper-conservative progression" in regard to returning to full strength.
"It's been very important to us to make it criteria-based, where he checks off certain boxes [and] can move to the next step," Colangelo said.
The Sixers have said he hasn't experienced a setback in his recovery. Colangelo said Embiid not playing is a result of being a "7-foot-2, 280-pound specimen that had knee surgery."
"It looks like if you walked into the gym, he could be playing five-on-five basketball," Colangelo said. "But once again, we are going to take our cues from people that know best."
Embiid's workouts have included shooting, posting up, putting the ball on the floor and step-back moves. These drills put quite a bit of force and torque on Embiid's knee. The Sixers have him performing the drills as a way to test the knee.
The team will ramp up the workload if his knee holds up well. Then it will become a matter of how much time he'll be on the court.
"How long are the workouts?" Colangelo said. "What is he able to sustain before fatiguing?"
He added that Embiid is "doing a lot on the court. More so than you would imagine based on some of the dialogue we are having today."
Embiid played in only 31 games last season before the team announced on March 1 that he would need season-ending knee surgery. His last game was Jan. 27.
He has a history of being injured. The third overall pick of the 2014 NBA draft, Embiid had missed the previous two seasons after two surgeries to repair the navicular bone in his right foot.
But he was starring last season before suffering the injury.
Embiid averaged 20.2 points, 7.8 rebounds, and 2.45 blocks per game, and he was nearly chosen as an all-star starter and reserve even though his playing time had been limited. The rookie center was held out of the second of back-to-back games in an effort to keep him healthy.
Despite his inability to remain healthy, Embiid could still receive a lucrative contract extension before the Oct. 16 deadline. He could receive a four-year deal in excess of $100 million.
"I'm cautiously optimistic that we can find common ground," Colangelo said. "But it will take common ground in order for something to get done."
But right now, the Sixers are saying there's no timetable to get Embiid on the floor. They haven't even determined a minutes limit or whether he'll play in back-to-back games. The preseason schedule begins Oct. 4 against the Memphis Grizzlies at the Wells Fargo Center.
The only thing the Sixers will say is that his health hasn't passed their requirements to play.
"He's not there," Colangelo said. "Will he be ramping that up through the preseason? Yes. How many games? We're not certain. Is he at every game? We don't know.
"This will be based on what we are told and what we get from medical professionals."