As the debate about biological men playing in women’s sports resurfaces, one of tennis’s top players is throwing her support behind tennis’s new sex test policy. Last month, the Women’s Tennis Association (WTA) introduced a new sex test policy that requires players to undergo a one-time genetic test for the SRY gene, which is found on the Y chromosome or those who were born biologically male. The test can be done through a cheek swab or blood test and players who refuse the test could face disciplinary action. It’s a reversal for the WTA, which has previously permitted transgender women, biological men who identify as women, to play in the league if their testosterone levels ranked below 2.5 nmol/L continuously for the previous two years.

Tennis star Aryna Sabalenka, who has been ranked #1 for over 90 weeks, voiced her support for the policy. “I think it’s really important to keep the fairness in our tour. Obviously, biologically, men are way stronger than women, so I feel like it would not be really fair for a woman to compete against a biological man,” she said at a press conference. “I believe it took them a little while to make this decision and I support it. If they want to test us all, I’m happy to do that; it’s pretty fair, and let’s keep it that way.” Players who test positive for the SRY gene may still be able to compete in tournaments if they can prove they have “Complete Androgen Insensitivity Syndrome or another disorder of sex development,” meaning they “have never experienced the physiological effects of either Male Mini-puberty or Male Adolescent Puberty.”

The WTA is just one of women’s leagues that have taken steps to keep biological men out of women’s sports, with the International Olympic Committee (IOC) updating their guidelines earlier this year and World Boxing requiring SRY testing in 2025 after athlete Imane Khelif won the gold medal in the Paris 2024 Olympics. Khelif’s win was controversial at the time after Khelif had previously failed a gender eligibility test in 2023.

Now the WNBA is facing pressure to define a woman after the league implied anyone identifying as a woman could join the league. Two former NBA stars, Enes Kantor Freedom and Royce White, have declared their eligibility for the WNBA’s 2027 draft to test the league’s commitment to gender inclusivity. Their supporters claim that both men would crush biological females in competition due to inherent biological advantages from being men while critics claim the men are making a mockery of trans athletes. The WNBA has yet to announce any new policies or definitions on what would qualify as a woman for the league.