Had it been a dive in the Summer Olympics, Gael Monfils would have scored himself no higher than a 5.0.

But coming as it did on the clay court of Roland Garros rather than a swimming pool, Monfils’s airborne lunge, in which his 6-foot-4 frame was fully horizontal to the hard-beaten ground, was a 10.0 on the scale of gravity-defying theatrics.

It came in Monfils’s second-round victory last week at the French Open. And it was the latest example of his rare athleticism — precisely the sort of athleticism that could help American tennis reclaim its prominence in the sport.

The challenge, say those charged with grooming the next generation of U.S. touring pros, is getting more exceptional young athletes to choose tennis over soccer, basketball and the myriad team sports available in schools and summer leagues.

It has become a familiar refrain as U.S. tennis fortunes wane. This year’s French Open, the season’s second major, has put that decline in stark relief, with no American man reaching the quarterfinals for the 11th consecutive year.

The United States has roughly five times the population of France but just one man, John Isner, ranked among the world’s top 50 tennis players. France has seven. And countries that were hardly deemed tennis powers a generation ago, such as Croatia and Canada, have more than one.

So what’s the solution for coaxing more promising young athletes to American tennis courts?

U.S. Davis Cup captain Jim Courier feels the sport has made huge strides on an international level, citing Rafael Nadal, Novak Djokovic, Roger Federer and Monfils — whom he calls “the greatest raw athlete that men’s tennis has ever had” — as athletes who would have excelled at any number of sports.

“Tennis has come a long way from the country club,” said Courier, 43, who counts two French Open championships among his four Grand Slam titles. “Tennis used to be a place where people who couldn’t succeed in football, basketball and baseball would go to have athletic success. It was the domain of the second-class athlete.

“We’ve come a long way from that space. Tennis is now full of first-class athletes because the game has gone global. And that wasn’t always the case when you looked at the tennis world.”

Still, it’s rarely the sport of choice among the most promising young American athletes. And Courier suspects no amount of marketing is likely to change that.

“There is no way that we’re going to make tennis cooler than the NFL: It’s not going to happen,” Courier said. “It comes down to parents. Athletes choosing tennis really is a function of parents introducing children to tennis. It’s not a sport that you pick up in elementary school.”

If Patrick McEnroe could go back 20 years and convert great athletes who ended up in other stick-and-ball sports to tennis, he would put a racket in the hands of NBA guard Dwyane Wade, Seattle Seahawks cornerback Richard Sherman and Pittsburgh Pirates center fielder Andrew McCutchen.

“It doesn’t matter how fast you can run or how high you can jump if you actually can’t time the ball,” said McEnroe, general manager of player development for the U.S. Tennis Association. “And obviously you’d like to see somebody that can move. I think that’s the way the game is going, with the speed and athleticism as opposed to brute strength and force.”

Son of a soccer player from Guadeloupe, the 177-pound Monfils was a dazzling tennis talent as a teen, when he won three of the four Grand Slam junior titles in 2004 (the Australian Open, French Open and Wimbledon).

Long, lean and lightning quick, the 27-year-old Monfils says he likely would have played pro basketball had he not become a tennis pro. He counts himself a major Carmelo Anthony fan as well as a world-class break-dancer. (A YouTube video of his “Dance-Off” during the French Open’s kids’ day last week drew more than 3 million viewers.)

Monfils is equally spontaneous and inventive on court, often conjuring up outlandish shots for the sake of the challenge when a high percentage one would do. That has worked to the detriment of a pro career that has been dogged by injury and inconsistency. And despite his athletic gifts, Monfils was stopped short in his Grand Slam pursuit again Wednesday, falling in a five-set quarterfinal to reigning Wimbledon champion Andy Murray.

Notes: For the second time in two days, Riverdale Park’s Francis Tiafoe, 16, served as hitting partner for eight-time French Open champion Nadal at Roland Garros. It was a 45-minute session roughly six hours before Nadal’s quarterfinal match against fellow Spaniard David Ferrer, and a capacity crowd of about 300 packed the three rows of stands on Court 4 to watch the workout. . . . American Stefan Kozlov, 16, advanced to the quarterfinals of boys’ singles with a 7-6 (7-5), 6-1 victory over Lee Duck-hee of South Korea. Born in Macedonia, the sixth-seeded Kozlov lives in Pembroke Pines, Fla., and is the last American standing in the tournament’s main and juniors singles draw.