There's the rookie wall, that time midseason when the grind of the schedule and enormity of minutes catch up to a player.
Joel Embiid never hit that. He didn't have the chance. His first season was cut short because of a knee injury after just 31 games.
This season Embiid is playing more basketball, more than he thought he would be at this point.
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"It's new," Embiid said following Tuesday's game in Charlotte. "I've got to get adapted to that. Never done it in my life."
Embiid has appeared in 53 of the Sixers' 64 games, including back-to-backs for the first time in his career. He has played nine straight games since the All-Star break when he participated in the Rising Stars Game, Skills Challenge and All-Star Game.
At 31.3 minutes per game at that frequency, it's a dramatic increase for someone whose playing time his first season was limited by medical restrictions.
"I think fatigue definitely has a part to say in some of his Joel's performances recently," Brett Brett Brown said Thursday.
Embiid's production has slowed as of late. He scored less than 20 points in four of his last five games (below his season average 23.4 points) and is shooting 41.0 percent from the field in March, down from 50.3 percent in February.
He made just five of a team-high 18 field goal attempts Thursday against the Heat, shooting under 30 percent in a game for the first time. He described his performance as "s---ty" and attributed it to his touches.
"I get frustrated when I don't get the ball," Embiid said. "But I've got to make sure that I stay up and that my teammates keep pushing me about playing harder even though I'm not getting the ball. That's on me. I don't think it has anything to do with fatigue."
It's hard to think, though, fatigue wouldn't catch up with him at some point. If minutes didn't take a toll on players, more than 17 would have played all 82 last season. Of that group, only six averaged more than 30 minutes per game.
There's no denying the difference without Embiid on the court as the Sixers vie for postseason seeding. But if he's not playing up to par, how much is more is he helping them than if he took a game off to recharge?
"We talk all the time about Joel," Brown said. "As far as a definitive plan (for rest), there is not one."
The Sixers' schedule affords them the flexibility to rest Embiid a few games before the postseason begins. Just four of their remaining 18 games are against current playoff teams, including back-to-backs this month against the Knicks and Nets followed by the Grizzlies and Magic.
It is more important for Embiid to be at full force when it really matters in the playoffs than getting fatigued in March in games that should be winnable without him.