Hainline said he's concerned that tennis courts are increasingly being repurposed for pickleball use, according to The Associated Press.

"It was a great, organic, grassroots movement," Hairnline said of pickleball's rise, "but it was a little anti-tennis."

The Associated Press notes that while pickleball was played at the French Open in May, it hasn't been welcome at the US Open, which is now underway in Queens.

And the USTA is going on the offensive with a new game of its own: Red Ball Tennis. The USTA plans to start piloting the game this spring, according to the organization's website. The game features a smaller, stringed racket, a lower net, and a larger, low-compression ball.

It's ideally played on pickleball courts, Hainline told the AP.

The head of the US governing body for pickleball didn't sound concerned about the prospect of Red Ball play 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," Pickleball USA CEO Mike Nealy told the AP.

There's also a third competing game in the mix: padel. But while gaining in popularity, padel is played on larger enclosed courts, meaning it's not competing in the same turf wars.

Neither the USTA nor USA Pickleball immediately responded to Business Insider's requests for comment.