What makes the match all the more magnetic is not only that both are from the USA (you can imagine the media frenzy across the Pacific), but that there is some solidarity between the two, too.

“I noticed Sloane I think years ago at TeamTennis maybe four years ago,” Serena revealed. “I saw her in the locker room. She was another black girl. I was like, ‘Hey!’ That’s when I first noticed her. ‘What up, girl’?”

This is not to say that Serena has guided Sloane to her current position as the world No.25 and a first Grand Slam singles quarterfinal, and she is certainly not about to start telling Stephens what to do.

But she has been, directly or indirectly, a presence in the 19-year-old’s life.

“I would need a better definition of the word ‘mentor,’ Serena joked. “But I just feel like being the older one, probably maybe some of the younger players look up to me. [But] it’s hard to be a real mentor when you’re still in competition. So I think it’s a little bit of everything.”

Stephens, similarly, sees it as a friendship.

“It’s normal,” she said. “We just talk whenever we see each other. Friendly stuff.”

“I feel no responsibility,” Serena said. “I doubt she has any expectations of me to be responsible for anything. I’m here to compete and do the best I can, as well as she. And she’s been doing really amazing. I’m really happy.”

Learning that it is one thing to play with Serena, and quite another to play against her, Stephens does admit she has reflected on their first meeting on court, a tight two-set loss in the Brisbane quarterfinals earlier this month.

“It wasn’t like, ‘Oh my God, I played Serena, I’m going to be so great at all these things because she just taught me so much’,” Stephens said. “But there were little things that you take and move on.”

And Serena learned from it too.

“I took a lot from that match,” Serena said. “She plays well. I feel like it will be another good match and a good opportunity for both of us.”

This sport has yielded many friendships between the older experienced player and the young up and comer, some more adult to child, some more friend to friend. Carlos Moya and Rafael Nadal, Andre Agassi and Andy Roddick, Ivan Lendl and Pete Sampras, Chris Evert and Tracy Austin, Tim Henman and Andy Murray.

“Agassi was my hero,” Roddick has said in the past. “It was surreal, like I was in a daze. My dad put this court together in our yard in Florida and Andre would come over and hit.”

Roddick has done the same himself, inviting Jack Sock to practice after beating the youngster at the US Open in 2011. “He told be I’ll be on that court many more times, that I’ve got a bright future,” Sock said. “Then he invited me to Austin to practice.”

Serena and Sloane are more likely to be found bantering in the locker room about how Stephens’ “really loud” demeanour on court compares to Serena’s “loud and outrageous” rather than on the practice court. But Stephens is adamant she is ready for round two against her sort-of-idol.

“She’s obviously one of the greatest players to ever play the game,” she said, matter-of-factly.

“Without all that, it’s still a tennis match. The court’s the same size. You’re still playing a regular person across the net.

“It just happens to be Serena.”