Mirra Andreeva previews sibling scrimmage with elder sister Erika at Wuhan Open

WUHAN, China—Mirra Andreeva can’t remember the last time she won a match against big sister Erika.

“Last time we played like a practice match, not just some exercises, like the real match, I think it was maybe three to five years ago, something like that,” she recalled at in her Dongfeng Voyah Wuhan Open press conference.

“I didn't win,” she added with comic flatness.

The latest Hologic WTA tour sister act will face off for the first time in an official match this week, but where a sibling is often an athlete’s first rival, the Andreeva family resolved long ago to keep it social between the sisters.

I'm an extrovert and she's introvert...For example, if there would be a choice to go somewhere to have fun or to stay in my bed, I would choose to stay in my bed. She will not even think about it! She will always stay at home and just do something alone or with the family. Mirra Andreeva on elder sister Erika

“It's not like we're nervous, it's like we're nervous about each other,” Andreeva clarified after a 7-6 (5), 6-3 win over hometown favorite Wang Xiyu.

“For example, if she does a lot of mistakes or I see she's unhappy or worried, I start to be worried for her. Then I cannot play normally. When she sees that some bad stuff happens to me, she cannot play normally, she cannot practice. We're just kind of too worried about each other when we practice when something goes wrong and we cannot focus on ourselves.

“Maybe in the future it will change. Maybe we will learn how to take advantage of it. But for now, it's like this.”

At least it will be until Wednesday evening when Mirra, seeded sixteenth, takes on Erika, a qualifier fresh off a main-draw win over Australian Open semifinalist Dayana Yastremska. Though Erika is three years older than Mirra, the younger of the Andreeva siblings has been the WTA’s breakout star since she reached a 1000-level fourth round last spring in Madrid.

The 17-year-old has only gotten stronger in the 18 months since, hiring former Wimbledon champion Conchita Martinez as her coach and stunning world No. 2 Aryna Sabalenka to reach her first major semifinal at Roland Garros. She won a silver medal in women’s doubles at the Summer Olympic Games in Paris and made her Top 20 singles debut on Monday.

Off the court, she has charmed fans and media with a youthfully madcap personality, revealing affinities for Andy Murray and Chandler Bing from “Friends.” Erika, she shares, is the more introverted of the two.

“I feel like she doesn't like to talk much,” she said. “I'm completely the opposite. I like to talk to people. I'm just always talking a lot. Sometimes I can be worried because I don't want to irritate people!

“She's more calm, maybe a little closed person. I think that would be the main difference, I would say.”

The contrast has also carried onto the court, with Mirra famously likening her game to Ons Jabeur, where Erika has seen herself more in Iga Swiatek—although their practices, however light, have revealed an evolution in the latter.

“I feel like now she's more aggressive,” Mirra argued. “I change the rhythm a lot. I just play in the moment. Like, I decide during the rally what I want to do. For example, there is a lob coming. I'm like, ‘Okay, I'm going to wait for it to bounce and then I'm going to take it.’ Then I see it's slow, so I'm, ‘Okay, I'm going to take a spin ball.’ I feel like I can change my decisions fast. Sometimes it's good. Sometimes it's bad.

“I feel like she has one strong plan for the match and she will do it until the match is over. Doesn't matter the score, doesn't matter the situation. She will just go for it, yeah, do whatever it takes to win. Me, I'm more kind of see what happens, then we're going to decide, all of that.”

Of course I'm curious to see who's going to win tomorrow. It's going to be a nervous match, for sure. For my parents, especially! Mirra Andreeva

For all her improvising, Mirra conceded there’s no one who knows her game better—jokingly calling the match-up a “nightmare.”

“I think it's going to be fun, of course, for the people who are watching, but it's going to be really stressful for the both of us I think,” she said.

“We decided that we're going to split the prize money for the second round. Whoever wins just goes forward. Of course I'm curious to see who's going to win tomorrow.

“It's going to be a nervous match, for sure. For my parents, especially!”