The Sixers need to get tougher on their young stars | Mike Sielski

For the 76ers, their five-game playoff loss to the Celtics was a great revealer, manifesting some obvious yet uncomfortable facts, and here are three at the top of that list: Markelle Fultz couldn't play. Ben Simmons couldn't shoot. Joel Embiid couldn't keep up.

Complain about Brett Brown's unwillingness to call timeouts all you like, but the broader and more meaningful implications of that Eastern Conference semifinals were born of the three players who are supposed to be the cornerstones of the franchise's future.

Fultz, the No. 1 pick in the 2017 draft, was consigned to the Sixers bench for the entire series, his mind and mid-range game still too much of a mess for him to be trusted on the court. Simmons, the No. 1 pick in the 2016 draft, finally encountered an opposing team that built a great, great wall between him and the basket, and funny enough, he and the Sixers paid for it. And by the end of Game 3, when his sluggish, slow-motion cut toward an in-bounds pass led to a turnover, Embiid was so gassed that the Sixers could have been forgiven for plying him with Shirley Temples during timeouts, in the hope that the sugar rush could get him through the final few minutes.

These developments weren't all that surprising. They had been concerns for a while, and they are part of a pattern that the Sixers have to break if they want to rise to the top of the NBA. They must begin making more demands of their best and most important players, and the free hand with which they managed and, in some cases, catered to these players has to become firmer.

Brown has acknowledged that this shift has to happen, revealing last week that he has pretty much pleaded with Embiid and Simmons to let him coach them, to let him push them to be better and tougher and more disciplined. The Celtics series — particularly the jagged-edge defense that Marcus Morris, Marcus Smart, and the rest of Brad Stevens' team deployed — should have reinforced Brown's message, but it can't be the end of the lesson. The Sixers, as they are, aren't good enough to win a championship, and it will take more than the splashy acquisition of a superstar or two for them to reach that level. It will take Embiid's improving his physical conditioning, Simmons' improving his jump shot, and Fultz's improving his overall game and psychological state. And it will take the Sixers' encouraging them to do so – and, if necessary, insisting on it.

The insisting, really, should have begun earlier. When the Sixers record was still subpar and expectations were still relatively low, it was easy for them to tout their young core in marketing campaigns, to treat and talk about Embiid and Simmons and Fultz as if they were the princes of Philadelphia basketball. The promise of what those players and, in turn, the team could be was enough to distract and tantalize everyone. But the time for deferring to them, for avoiding some hard truths and conversations, passed long ago.

After suffering that broken orbital bone, Embiid should have been told that, since he had to wear a facial mask during games, he had to wear a facial mask during practices, too, regardless of how cumbersome he found it. After breaking his foot in 2016, Simmons had a full year to refine his shooting form. Somehow, his left elbow still flares outward as if he were muscling for room on a crowded subway train. Somehow, he still doesn't dare square up for an open 17-footer.

Now, after the Sixers spent months tip-toeing around the real reasons that he couldn't contribute as a rookie, Fultz should have a reserved spot on the team's summer-league roster. He could use, and should use, the training to regain his confidence, to ease his way into a bigger role next season. Yet even this course of action is an open question, apparently because a No. 1 pick might consider having to play a second season of summer-league ball to be some kind of insult.

"Every athlete is looked at a little bit differently, in terms of trying to formulate a path and a plan," general manager Bryan Colangelo said. "And as you know, there's just different levels of …"

Here, Colangelo paused, choosing his words carefully.

"As you look at players who play in the summer league, year one to year two, generally there has something to do with draft status and where players were picked. That might be a factor in this."

It shouldn't be any factor at all. No, Simmons didn't play a second summer-league season. He didn't have to; once his foot healed, he was ready. Fultz's situation is different. He forgot how to shoot. He needs that extra preparation, and given his lack of leverage after his lost season, he's in no position to complain about any double standards.

Truth be told, none of those three is, not after the way this season ended. Understand: No matter whom the Sixers sign or trade for this offseason — LeBron James, Kawhi Leonard, Paul George — if that player notices that a sense of entitlement has settled in, he's going to say something. He's going to speak up, and he'll have the credibility to call out anyone he has to, and if the Sixers think that Boston delivered the only reality check that Joel Embiid, Ben Simmons, and Markelle Fultz need, just wait.