Team USA warms up during a training camp at Qudos Bank Arena on Saturday in Sydney, Australia. Photo: VCG

So many NBA headliners from the USA are skipping the Basketball World Cup in China that they would assemble a formidable all-star squad of their own.

But it is nothing new for the ­Americans as they seek a third ­consecutive crown in the global showdown that runs from Sunday to September 15. And from past experience, it could even pave the way for a new US figurehead to emerge.

LeBron James, Kawhi Leonard, ­Stephen Curry, James Harden, ­Anthony Davis, Russell Westbrook and Paul George are among those who opted out. Kevin Durant, Kyle Lowry and Klay Thompson are injured.

The World Cup final comes only two weeks before most NBA training camps open, with the first games of the 2019-20 campaign on October 22.

Adding to the usual pressures of preseason were the large number of transfers by top stars in the off-season and an up-for-grabs mentality in the Western Conference, where a half-dozen revamped clubs are legitimate NBA title contenders.

"I think most of the star players, they are trying to save their energy. I think that's the main reason they are dropping out," said Sam Mitchell, an NBA TV analyst who played in the league in 1989-2002 and coached for parts of six seasons.

"There are 80 percent of the players on the star teams who have a chance to compete for a championship. For you to go play in the world championships, risk getting injured... it's a lot to ask."

Some players never considered this year's team, including Lakers star James, who began filming Space Jam 2 in late June. 

The 34-year-old won Olympic gold in 2008 and 2012 and had played in eight consecutive NBA Finals until this year.

Many players said they needed the off-season to integrate with their new clubs or new teammates.

"I think other guys looked at it like, 'Why would I want to go potentially be the face of what could be a losing roster?'" said C.J. McCollum, who also withdrew from the team, on a podcast of ESPN's Adrian Wojnarowski.

'Dream Team' to 'B team'

Former San Antonio Spurs coach Gregg Popovich, who is guiding the US team for the first time, has been forced to name a squad of emerging talents.

Popovich and his men were given a jolt on Saturday when they were stunned 98-94 by Australia in Melbourne, snapping a run of 78 consecutive American wins in major competitions and exhibition games.

"Nobody wins forever," said Popovich, whose team bounced back to beat Canada 84-68 on Monday.

This may be no "Dream Team" - the name given to the star-studded 1992 Olympic side - but young talent has done the job in past USA World Cup campaigns.

The 2010 squad was derided as a "B" team but won the crown behind future NBA superstars Durant, Westbrook, Curry and Kevin Love.

In 2014, the victorious USA team included Davis, Harden, Thompson, Curry and Most Valuable Player Kyrie Irving.

Mason Plumlee is the only 2014 World Cup player back for the Americans, while Kemba Walker is the lone all-NBA player on the squad.

Harrison Barnes is the only ­member of the gold ­medal team in the lineup at the 2016 Rio de Janeiro Olympic Games, adding to doubts back home that the US can make it three world titles on the spin.

Spanish center Marc Gasol, who helped Toronto to the NBA crown, told The New York Times that he expects the USA to use the skepticism as motivation in China.

"Even with all the guys that dropped out... they are still super-talented physically and technically," Gasol said. 

"They are pretty well coached as well. So you put it all together and it's a great team."