Call it Kyrie Irving on the upper and Nick Kyrgios on the outsole for the upcoming Nike Vapor X Kyrie 5 tennis sneaker.

The NBA and tennis stars connect on their Australian roots—Kyrgios and Irving were both born there—in collaborating on a new on-court tennis sneaker for Kyrgios and a matching player-edition colorway that Irving will wear as part of his Kyrie 5 line.

Irving will show off the style first, with plans to wear his PE version of the shoe on Jan. 7 at home against the Brooklyn Nets. The one-off exclusive for Irving simply marks the entry into Kyrgios wearing his new Vapor X Kyrie 5 throughout the first tennis Grand Slam of the season, the Australian Open, starting Jan. 14 in Melbourne.

Kyrgios, a major NBA fan known for his love of the Celtics, says this collaboration was basically the best of all worlds for him. “Yeah, it’s arguably the biggest moment of my career,” the 23-year-old says. “I’m going to go out in front of my home crowd wearing the tennis shoes that share the name with my favorite basketball player. Representing Kyrie and myself at the same time, in front of such a big stage, is pretty crazy.”

Being a major basketball fan, Kyrgios says he was always attracted to the style basketball players wore on and off the court. “I wanted to be like those guys,” he says. “They were my role models, so I wore the shoes they did.”

The collab started in early 2018 when NikeCourt, the tennis division of Nike, decided to embrace Kyrgios and his anti-country club personality. “We started diving into Nick and his interests and personality,” says Alex Restivo, NikeCourt footwear product director. “He always talks about his alter-ego, where he wanted to grow up and become a basketball player. He is always talking basketball, talking Celtics, and he loves Kyrie Irving.”

Nick Kyrgios with the Nike Air Zoom Vapor X Kyrie 5
Image via Nike

So NikeCourt crossed the paths at Nike HQ to the basketball team to discuss the next steps. The Australian connection made a natural collaboration link, timed with the Australian Open.

As the two design teams started comparing notes, they both realized there was plenty of crossover between the sports when it comes to creating performance product. “One of the coolest parts of this project was looking at the Kyrie 5 and the upper and main features in the flytrap containment system,” Restivo says. “In tennis, we do everything we can to keep players locked down, and this flytrap system has such a bold, unique look and provides such an amazing innovation.”

So, the Kyrie flytrap upper migrated from the Kyrie 5 onto the Vapor X, while retaining the Vapor X outsole, midsole, and foot frame. “It brings basketball performance to tennis and blends the innovations and styles,” Restivo says. Kyrgios first wear-tested the mash-up in September in Cincinnati, immediately falling in love with the style.

The Vapor X version isn’t a direct one-for-one take on the Kyrie 5, though. It was edited on the upper for tennis, with a lower collar height and additional durability pieces specific for tennis on the hard court.

From there, though, expect a strong Kyrie aesthetic. The heel mimics the molding and tattoo detailing of the Kyrie 5 and Irving’s signature is found on both the flytrap and the translucent underside of the outsole. The NikeCourt logo on the tongue—a stylized tennis court—now comes embedded with the Kyrie logo. “You haven’t seen this before in Nike history,” Restivo says. “It is a good homage to the blend of cultures between basketball and tennis.”

The tennis version includes a sockliner with a graphic of a basketball sitting on a tennis racket string bed. The predominately white shoe with black accents also boasts plenty of Nike’s “Hot Lava,” the pink made famous by Andre Agassi during the French Open in 1990. The "Hot Lava" will extend beyond just the Vapor X Kyrie 5 and into the entire outfit Kyrgios will wear on court in Melbourne.

For Irving, the player edition comes as part of his effort to tell more personal stories with the Kyrie 5 line. "I loved the Vapor X ‘Kyrie 5’ from the moment I first saw them," Irving told Complex. "The connection of Australian roots and that we have respect for one another’s games makes the blending of these two shoes a perfect match."

“With the colorways and the stories these relay, I’m trying to be more honest,” Irving says. "The importance is making these relatable. And, at times, I want to support others in sharing their stories."

But for NikeCourt and Kyrgios, the sneaker will turn into a mainstay for 2019. The tennis version goes on sale Jan. 14. Kyrgios will wear the style all season, changing up the colorways and bouncing between tennis-specific and basketball-specific stories throughout the season.

“A common theme that always comes up is our tennis players have an obsession with the game of basketball,” Restivo says. “When the connection and story is right, we want to act on this. This will be a lot more unexpected in the market than Jordan and Federer (the 2014 Nike Zoom Vapor AJ3).”

Nike Vapor X Kyrie 5 (On-Foot)
Image via Nike

That love of basketball has already given Kyrgios a unique sneaker standing in the tennis world. A Nike athlete his entire life, Kyrgios has an extensive sneaker collection and is the only ATP player who walks out on the court in different sneakers than what he plays in—generally a pair of Jordans.

“It started when I was young,” he says. “I had this superstition that I couldn’t wear my tennis shoes before or after a match. I feel like you can kind of gauge someone’s personality by the kicks they wear. That was a little bit of a sneak preview of what I was about before I started playing.”

Now, though, Kyrgios has reached the pinnacle of his sneaker life. “This shoe is number-one in my collection,” he says. “The fact that this is a collaboration with Kyrie is not even close anymore. I’m super excited. All my old friends can appreciate how special this moment is to me.”

For all of 2019, the Kyrgios personality will extend beyond the shoes he walks into the stadium wearing. His on-court persona will also include a healthy mix of Kyrie.