The topic of transgender athletes competing in women’s sports has dominated sports discourse in recent months. But no sport has been as directly impacted as women’s tennis after the WTA announced in July that it will mandate genetic sex testing for all its players.

At the Montreal Open, several top WTA players have been asked their thoughts after the rule changes. World No. 1 Aryna Sabalenka said she supported the tour’s decision.

“I think it’s really important to keep the fairness in our tour. It’s obvious that biologically the men are way stronger than women, so I feel like it would be not really fair for the woman to compete against biological men,” Sabalenka said.

The WTA’s Women’s Eligibility policy on the testing reads: “This policy distinguishes between biological sex and gender identity, and between biological females and biological males, solely to the extent necessary to ensure that the policy is clear and has its intended effect. There is no intent to disrespect or question the gender identity or the dignity of any person.”

She added: “If they want to test us all, I’m happy to do that, it’s pretty fair, and let’s keep it that way.”