Joel Embiid had a rough Team USA debut against Serbia. His Olympics might not get much better.

LILLE, France — Joel Embiid ran out of the tunnel here at Pierre Mauroy Stadium on Sunday, and he was booed. He touched the basketball, made a post move, or ran a dribble-handoff with LeBron James, and he was booed. He took a shot, and he was booed. He scored four points, and he was booed. He committed three fouls and missed three free throws, and he was really booed. Imagine how much he’d have been booed if he’d actually played a decent game.

There’s no getting around it: Embiid did not have a decent game in his Olympic debut: the United States’ 110-84 victory over Serbia before 27,000 spectators who were at their loudest at Embiid’s expense. Why he didn’t is open to some conjecture and speculation, in part because Embiid did not speak to any reporters after the game.

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If you’re inclined to give Embiid the benefit of the doubt, then it’s easy to find reasons he was as sluggish and out of sorts as he was Sunday. He had missed practice the day before with what U.S. coach Steve Kerr called “an illness.” And not long ago, during a New York Times podcast, he said that, because he returned so quickly from surgery on the meniscus in his left knee, he was never close to 100% during the final days of the 76ers’ regular season and their first-round loss to the Knicks.

But there are trends with respect to Embiid that made what the world saw Sunday both familiar and, if you’re hoping for him to show off his talent and dominance in this tournament, concerning. He does not appear to be in peak physical condition, which suggests that he is not in peak physical condition, which makes him an ill fit for the style that Kerr wants to play — and that turned Sunday’s game toward the U.S. Serbia got out to a 10-2 lead as Embiid labored on defense, front-rimmed two free throws, and threw a terrible pass that led to a turnover and basket.

More, it’s fair to wonder how much Embiid’s game, even at its optimum level, would benefit the U.S. here. He decided to play for Team USA — not for France, as the folks around here keep reminding him — because he wanted to be among the best of the best in his adopted country. But being among those players might mean that Embiid’s role has to change. To a degree, it’s unfair to look at Nikola Jokic’s 20-point game Sunday and compare it to Embiid’s forgettable day. Jokic is the nucleus of Serbia’s team. Everything funnels through him when he’s on the floor; he’s that much better than his teammates.

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Embiid isn’t. He’s great, but he’s one of several guys on the U.S. roster who are in the Greatest Player on the Planet conversation. The Sixers run their offense through him, too, just like Serbia and the Denver Nuggets do with Jokic, but Embiid isn’t the facilitator that Jokic is. With the Sixers, he hasn’t had as much of a chance to be. So for them, he holds the ball at the lane’s elbow or in the post or at the top of the key, and it often has to be that way because … well, what has the alternative been? Kicking the ball out to Furkan Korkmaz or DeAnthony Melton?

The thing is, there are no Furkans on the U.S. national squad, and there are few officials, if any, looking to bail Embiid and his teammates out of a bad possession by sending him to the foul line. Two of Embiid’s U.S. teammates, Bam Adebayo and Jrue Holiday, both of whom have more experience with international basketball than he does, affirmed a simple truth of this tournament: FIBA hoops are more physical than NBA hoops. “You can tell the difference,” Adebayo said. There’s no defensive-three-seconds violation in international play. Referees aren’t as apt to call the kinds of fouls that have been routinely called, and that Embiid has routinely drawn, in the NBA.

In the third quarter Sunday, Embiid had his best moment when he caught the ball on the right post/baseline against Jokic, power-dribbled toward the middle, and dropped in a fadeaway over Jokic, who fouled him. Embiid then threw his arms in the air in an It’s about time gesture. That kind of outburst won’t get him anywhere in this tournament, and the contrast between his performance and behavior and that of another teammate who had been at less than full strength was striking.

After missing all five of Team USA’s exhibition games with a sore calf, Kevin Durant was brilliant Sunday, making his first eight shots from the field and scoring 21 first-half points in a pure and perfect display of offensive basketball. “KD was phenomenal,” James said. “It was like he never missed a beat or a practice.” No one could say the same about the target of all that booing.