A former NCAA All-American swimmer, Riley Gaines, is attacking Megan Rapinoe for her support of transgender women in female sports, saying the soccer star would not willingly sacrifice her career so a biological male could take her place. 

On March 8, Ms. Rapinoe said in a tweet that “trans kids” are not a threat to women’s sports, and that instead of focusing on them elected officials needed to protect women from “unequal pay, sexual abuse, and lack of resources.” Ms. Rapinoe has been a professional soccer player for 15 years and has gained national attention for her advocacy for equality between men’s and women’s sports. 

In response to the tweet, Ms. Gaines said Ms. Rapinoe “personally has nothing to lose” in the fight against biological men in women’s sports because she is a lesbian. 

“It’s worth noting that 1) you are done playing sports competitively and 2) because you aren’t sexually attracted to men, you will never have a daughter to defend,” Ms. Gaines said in a now-deleted tweet. “To me, this simply looks like virtue signaling.”

In a follow-up message, Ms. Gaines said that she “can respect opinions that differ” from hers, but “can’t help but think Megan Rapinoe would genuinely shiv any male who tried to take her spot on the US Women’s National Team.”

Ms. Rapinoe has defended the inclusion of biological men in women’s sports since it became a salient national issue last year after a transgender swimmer, Lia Thomas, won the NCAA women’s swimming championship. Ms. Gaines has become outspoken against transgender athletes since losing that championship to Ms. Thomas. 

In an interview with Time magazine last year, Ms. Rapinoe said conservatives who are pushing bans on transgender women in female sports are “consistent” and “relentless.”

“I would also encourage everyone out there who is afraid someone’s going to have an unfair advantage over their kid to really take a step back and think what are we actually talking about here,” Ms. Rapinoe said. “We’re talking about people’s lives. I’m sorry, your kid’s high school volleyball team just isn’t that important. It’s not more important than any one kid’s life.”

Ms. Rapinoe added that transgender women competing in female sports is not a widespread phenomenon, and should not be met with the amount of scrutiny it has received in recent years. “Show me the evidence that trans women are taking everyone’s scholarships, are dominating in every sport, are winning every title. I’m sorry, it’s just not happening,” she said.

Ms. Gaines gained national attention in recent days after allegedly being assaulted at San Francisco State University. She was invited to speak on the unfairness of having transgender women compete against biological women like herself. 

Ms. Gaines posted a video of the attack online, where she can be seen fleeing a classroom with police by her side as a large group of transgender rights activists chase her down a hallway. 

“The prisoners are running the asylum at SFSU,” Ms. Gaines wrote on Twitter. “I was ambushed and physically hit twice by a man. This is proof that women need sex-protected spaces.” 

In another video, Ms. Gaines can be seen rushing down a hallway protected by two law enforcement officers, who then unlock a door and barricade her inside. Dozens of protesters remained outside of the room where Ms. Gaines was held, demanding payment in exchange for her safe passage from campus. She was locked inside for three hours before she was able to leave.

Ms. Gaines’s husband, Louis Barker, told Fox News that he was frustrated police could not protect his wife. “She told me she was hit multiple times by a guy in a dress,” Mr. Barker said. “I was shaking. It made me that mad. It makes me sick to feel so helpless about it. She was under police protection and was still hit by a man wearing a dress.”

The day after Ms. Gaines was assaulted, the university sent out an email message that offered resources for the “discord, anger, confrontation and fear” the former swimmer had caused. 

“Thank you to our students who participated peacefully in Thursday evening’s event,” the vice president for student affairs, Jamillah Moore, wrote. “It took tremendous bravery to stand in a challenging space. As you reflect, process, and begin to heal, please remember that there are people, resources and services available and ready to receive our Gator community.”

Ms. Gaines has since said that she is considering filing a lawsuit against the university and its police force.