As the U.S. Open opened this week with more than a million tennis fans expected for the sport’s biggest showcase, the game’s leaders are being forced to confront a devastating fact — the nation’s fastest-growing racket sport (or sport of any kind) is not tennis but pickleball.

The game has seen participation boom 223% in the past three years.

“Quite frankly, it’s obnoxious to hear that pickleball noise,” U.S. Tennis Association President Dr. Brian Hainline grumbled at a recent state-of-the-game news conference, bemoaning the distinctive pock, pock, pock of pickleball points.

Pickleball, an easy-to-play mix of tennis and ping pong using paddles and a wiffleball, has quickly soared from nearly nothing to 13.6 million U.S. players in just a few years, leading tennis purists to fear a day when it could surpass tennis’ 23.8 million players. And most troubling is that pickleball’s rise has often come at the expense of thousands of tennis courts encroached upon or even replaced by smaller pickleball courts.

“When you see an explosion of a sport and it starts potentially eroding into your sport, then, yes, you’re concerned,” Hainline said in an interview with The Associated Press. “That erosion has come in our infrastructure. … A lot of pickleball advocates just came in and said, ‘We need these tennis courts.’ It was a great, organic grassroots movement but it was a little anti-tennis.”

Some tennis governing bodies in other countries have embraced pickleball and other racket sports under the more-the-merrier belief they could lead more players to the mothership of tennis. France’s tennis federation even set up a few pickleball courts at this year’s French Open to give top players and fans a chance to try it out.

But the USTA has taken a decidedly different approach. Nowhere at the U.S. Open’s Billie Jean King National Tennis Center is there any such demonstration court, exhibition match or any other nod to pickleball or its possible crossover appeal.

In fact, the USTA is flipping the script on pickleball with an ambitious launch of more than 400 pilot programs across the country to broaden the reach of an easier-to-play, smaller-court version of tennis called “red ball tennis.” Backers say it’s the ideal way for people of all ages to get into tennis and the best place to try it is (wait for it) on pickleball courts.

“You can begin tennis at any age,” USTA’s Hainline said. “We believe that when you do begin this great sport of tennis, it’s probably best to begin it on a shorter court with a larger, low-compression red ball. What’s an ideal short court? A pickleball court.”

And instead of the plasticky plink of a pickleball against a flat paddle, Hainline said, striking a fuzzy red tennis ball with a stringed racket allows for a greater variety of strokes and “just a beautiful sound.” Players can either stick with red ball tennis or advance through a progression of bouncier balls to full-court tennis.

“Not to put it down,” Hainline said of pickleball, “but compared to tennis … seriously?”

So what does the head of the nation’s pickleball governing body have to say about such comments and big tennis’ plans to plant the seeds of its growth, at least in part, on pickleball courts?

“I don’t like it but there is so much going on with pickleball, so many good things, I’m going to stick to what I can control, harnessing the growth and supporting this game,” said Pickleball USA CEO Mike Nealy.

Among the positive signs, Nealy said, is the continuing construction of new pickleball courts across the country, raising the total to more than 50,000. There’s also growing investment in the game at clubs built in former big-box retail stores, pro leagues with such backers as Tom Brady, LeBron James and Drake, and the emergence of “dink-and-drink” establishments that tap into the social aspect of the game by allowing friends to enjoy pickleball, beer, wine and food under the same roof.

“I don’t think it needs to be one or the other or a competition,” Nealy said of pickleball and tennis. “You’re certainly going to have the inherent frictions in communities when tennis people don’t feel that they’re getting what they want. … They’re different games but I think they are complimentary. There’s plenty of room for both sports to be very successful.”

Top-ranked American tennis player Taylor Fritz agreed. “There are some people in the tennis world that are just absolute pickleball haters, and that’s fine. But for me, I don’t really have an issue with pickleball. I like playing sometimes. … I don’t see any reason why both of them can’t exist.”

The relative health of tennis and pickleball is calculated by the Sports & Fitness Industry Association, a marketing research group whose annual survey of 18,000 Americans on their preferences of physical activity has been widely cited for decades.

Though the group’s President and CEO Tom Cove refused to hazard a guess on if or when pickleball could overtake tennis, he said the American pickleball boom is unlike anything his organization his ever seen and several key stats suggest it could be poised to keep going.

For starters, though the initial growth of pickleball was fueled during the coronavirus pandemic by retirees looking for a socially distanced, low-impact way to get some exercise, the growth now is driven by those ages 18 to 34, with a million new players 17 and younger added last year. Also, of the current 13.6 million pickleball participants in SFIA’s survey, the core number, those who play eight or more times a year, is a robust 4.8 million.

But perhaps more important than any stat, Cove said, is that pickleball puts up almost no barriers to entry. Equipment is relatively cheap, the game can be played almost anywhere, even on a driveway, and it takes almost no time to start having meaningful games with players of all ages and skill levels. That’s unlike nearly every other sport, including tennis, which can often take months of practice to learn, be physically demanding and require finding players of similar skill level to play competitive matches.

“Pickleball has a unique quality to give enjoyment very early,” Cove said. “People figure it out and after one or two times. They say, ‘I like to play. It’s fun and I can do this. There’s enough competition, but not too much. There’s enough skill but not too much. There’s enough urgency but it doesn’t make me feel like I’m going to fall over. And I like the social part.”’

The USTA is seeking to capture some of that vibe as it charts tennis’ future. The game is coming off its own 10% growth over the past three years, according to SFIA’s survey, and the USTA has a goal to increase its ranks from 23.8 million to 35 million players — about 1 in 10 of all Americans — by 2035.

Building that base starts with outreach like a special “red ball” demonstration court set up next to stadium Court 17 at Flushing Meadows. A game that was once used almost exclusively to introduce children to tennis is now being promoted to adult U.S. Open fans — among the same people currently flocking to pickleball.

“I have to say, I kind of like it better than pickleball,” 27-year-old Angelique Santiago of Boston said after her first-ever session of red-ball. “The ball is softer compared to the hard pickleball. The tennis racket has a softer feel. It’s just easier to get into a rally. … I’d definitely play it again.”

Such comments are music to the ears of the USTA’s Hainline, who says comparing tennis to pickleball in terms of skill, nuance and athleticism is “like comparing apples to potatoes.”

“We want to present another option,” he said, “and let the people choose.”