The WNBA is moving towards letting biological males play on its teams, and female sports pioneers are warning about the dangers.

Leigh Ross-Dakich, a famous softball player and coach, warned that biological males taking roster spots from females is a bad idea.

Ross-Dakich said, 'Let's see what happens if we have one league. Girls will get left behind.'

Martina Navratilova says Billie Jean King's views on trans athletes do not match her own words.

Leigh Ross-Dakich shares her thoughts on WNBA coaches who want biological males to play in the league, saying females would be 'left behind'.

There are physical differences between men and women, which is why biological males should not play in female sports.

Ross-Dakich and tennis legend Martina Navratilova do not understand why some people support biological males in female sports.

Billie Jean King is a tennis star who competed in the 'Battle of the Sexes' match in 1973.

Ross-Dakich thinks current players do not understand the struggles women faced in the past to have their own sports leagues.

Megan Rapinoe says efforts to stop trans athletes from playing in women's sports are an attack on women.

Billie Jean King and Megan Rapinoe can say what they want without losing their jobs, but their views may harm female sports.

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If leaders do not change their views, Ross-Dakich thinks the results will be very bad.

Ross-Dakich said that if biological males play in female sports, women will lose their jobs and their sports teams.

Joe Kinsey is a senior director at OutKick.