From the second-floor dining room of Lo Spiedo, nestled just inside the entrance to the Navy Yard complex, you didn't have to stand up to glance out a window and see the facade of Lincoln Financial Field. On Sunday, a young athlete who had pretty much been a mystery to Philadelphia had himself a hell of a debut at that stadium. Aside from a few quick peeks, mostly during practices and before games, people outside the organization hadn't seen much of what he could do. But those who had drafted him and who coach him had insisted, whenever asked, that he was capable of making an immediate and positive impact on his team.

And on Thursday, 76ers coach Brett Brown sat at the head of a table in Lo Spiedo and talked about Joel Embiid.

"I wouldn't say that, at this stage, it's mysterious or unknown in the environment we've been seeing him," Brown said during a meeting with media members. "The speed of an NBA game, going against NBA players, will reveal more. . . . But in the world I have seen him, I feel like I get it. I feel like I know what he can do."

For two years, the navicular bone in Embiid's right foot was his Sam Bradford. From the moment the Sixers selected Embiid with the No. 3 pick in the 2014 draft, that bone - and its stubborn refusal to heal properly - blocked him from beginning his pro career. No more, Brown reaffirmed. Embiid will be ready to practice when the Sixers begin training camp at Stockton University on Sept. 27. He is on track to play in their first preseason game, on Oct. 4 against the Boston Celtics. And with those benchmarks, the ambiguity around him will begin to melt away, just as it did Sunday for Carson Wentz and the Eagles against the Cleveland Browns.

More than even Ben Simmons, Embiid promises to be the most intriguing aspect of the Sixers' season, and arguably the most important. He hasn't played in an official basketball game since March 1, 2014, when he was a freshman at the University of Kansas, and there will be what Brown called "parameters" for his playing time this season, including the likelihood that he will sit out the second of back-to-back games. But everyone, Brown included, has a good idea of what Simmons will look like on the court after his full season at LSU and several summer league games, what his strengths and weaknesses are. He will grab a rebound and lead a fastbreak, flick some dazzling passes to teammates, and opponents will dare him to take jump shots. Everyone knows this about him going in, because this is what everyone has already seen.

Embiid is another matter. If Simmons develops into a superstar, the Sixers could become a relevant NBA franchise again, a possible playoff team. If Simmons and Embiid develop into superstars, the Sixers could become something more: one of the few teams in the top-heavy NBA capable of winning a championship. Yet those two years of surgery and recovery and rehabilitation make it harder to remember why Embiid, had he remained healthy, would have been the No. 1 pick in that '14 draft class, and why Sam Hinkie and the Sixers were willing to risk so high a selection on a player whose body seemed bent on betraying him.

The breadth of skills that Embiid has shown the Sixers in the comfy confines of the practice gym leaves Brown wondering about how best to use him on offense. Backing down a defender in the post to dunk or feather a jump-hook over him, catching the ball on the block and turning and facing the basket and rising up for a jump shot, running the floor for a catch-and-shoot three-pointer or a creative play off the dribble - Embiid, at 7-foot-2 and 275 pounds, already appears to have mastered them all. And he is still just 22. As several Sixers players worked out early Thursday afternoon, Brown watched from the sideline. With him were Charles Barkley, Billy Cunningham, and Jim O'Brien. You've been doing this a long time, Brown said to Barkley. Who do you think he is?

"And you both sort of struggle coming up with an example," Brown said. "I think we're going to learn a lot more when the lights go on."

No, we'll learn a little bit more at first, just like we did Sunday with Carson Wentz. Then a little bit more . . . then a little bit more . . . until the reality of who Joel Embiid is and what he can do becomes obvious and undeniable and perhaps marvelous. That is the hope, the same one that the Eagles have for Wentz, and the challenge with both players is to remind yourself that each of them has a long way to go, even as everyone finally gets some glimpses of the greatness that might yet materialize out of all that mystery.

@MikeSielski