“He can’t play at that weight, it’s too much stress on his knees,” Charles Barkley said of the Pelicans' Zion Williamson. (Ethan Miller/Getty Images)

It’s probably premature to call it “Weight-gate,” but the subject of Zion Williamson’s physique and level of conditioning has continued to loom large in NBA chatter. The latest to weigh in, as it were, was Charles Barkley, who said Tuesday that both the Pelicans rookie and 76ers center Joel Embiid need to slim down.

The man who brought the “Round Mound of Rebound” nickname with him to the NBA knows a thing or two about carrying extra poundage, and began his discussion of Williamson by saying of the start to his own pro career in 1984, “I was fat.”

By contrast, Barkley claimed in an appearance on ESPN, Williamson “doesn’t look fat at all.” Yet he followed that assertion by saying of the No. 1 draft pick, who was listed at 6-foot-7 and 285 pounds during his one season at Duke, “I hear he weighs 280 — he can’t play at 280 in the NBA.

“He can’t play at that weight. It’s too much stress on his knees,” Barkley continued. “He’s so big and he’s so strong, but everybody in the NBA is big and strong.”

The comments echoed those made by a scout who spoke to The Washington Post’s Ben Golliver at the NBA Summer League in Las Vegas. “There’s no nice way to say [Williamson] has to lose weight,” the scout said. “But he has to lose weight.”

Williamson did not get much of a chance to do so in the summer league after knee-to-knee contact sent him to the sideline after he played just nine minutes. That wound up being enough time for some observers to express alarm over his appearance, given that his unusually bulky physique had already generated questions about his potential career longevity.

Meanwhile, concerns about Embiid’s conditioning are far less hypothetical and have been a frequently raised topic over the past two seasons. In May, during Philadelphia’s heartbreaking, second-round loss to the Raptors, a person familiar with the situation told The Post’s Candace Buckner that the 7-foot Embiid had to work to get down to an ideal playing weight of 275 pounds.

Barkley said Tuesday that the 76ers’ success this upcoming season will come down to Embiid and teammate Ben Simmons, who “has got to work on his game,” specifically his outside shooting.

A longtime standout for the 76ers in his own right, Barkley recalled that when he first got to Philadelphia, Moses Malone — the “most important person in my life, basketball-wise” — told him, “You’re fat and you’re lazy.” Barkley said he was compelled to lose 50 pounds, and “the rest was history.”

“I wonder, in Philadelphia, who has the courage and the chutzpah to tell Joel Embiid, ‘Yo, man, you got to get in shape,’ ” Barkley said.

That led to a question about Williamson, with ESPN’s Mike Greenberg bringing up recent comments by Duke Coach Mike Krzyzewski, who said the former Blue Devil “never should’ve played” in the summer league. Because Williamson had “been on this circuit of awards” following his sterling freshman season, Krzyzewski said, he wasn’t “in the playing shape or the mental shape to play” in Las Vegas.

Williamson’s brief appearance at summer league was enough for ESPN analyst Seth Greenberg to say, “You can’t improve unless you’re in shape, and he is not in shape. … Right now, he’s in condition to get hurt, not to be a great player.”

Doug Gottlieb of Fox Sports 1 said recently that Williamson “better buy a ‘body guy,' ” whose job it would be to “follow him around and keep him in shape.” Gottlieb added that the Pelicans star would also want to “have a chef” because “he has to lose weight; otherwise he runs the risk of those premature injuries.”

“I don’t know what Zion’s perfect body weight is going to be,” Barkley said before getting a laugh by adding, “I thought 300 was my perfect playing weight in college.”

“I had to lose 50 pounds to become a Hall of Famer,” Barkley continued. “I think [Williamson has] got a great system down in New Orleans. I love [head of basketball operations] David Griffin and [Coach] Alvin Gentry, but they’re going to have to come up with a comprehensive plan to see what the perfect playing weight is.”

The good news for Williamson is that he’s arriving in the NBA as such a figure of fascination that even the briefest of stints in the summer league, months before he will need to be in peak form for the start of the regular season, has been enough to spark animated discussions around the basketball world.

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