(NewsNation) — Lia Thomas, 22 — who is transgender — smashed Ivy League swimming records this year as a member of the University of Pennsylvania women’s team. But her goal of becoming an Olympian is creating divisions in her sport.

John Naber, a former NCAA swimming champion, four-time gold medal winning Olympian and a member of the U.S. Olympic Committee, said he would advocate against letting her swim against women.

“I hope that Lia feels included and there’s a place for her somewhere, but I do not think that she should be allowed to compete against the other women at the Olympic level,” he said.

Recently, the NCAA announced Thomas is eligible to compete at the championships and that it would not change its rules for the 2022 swim season because it “could have unfair and potentially detrimental impacts on schools and student-athletes intending to compete in the 2022 NCAA women’s swimming championships.”

But the debate about whether Thomas should be allowed to compete against women is reaching a boiling point. Two advocacy groups — the Women’s Sports Policy Working Group and Champion Women — released two petitions pushing for “fairness and safety for females” and not “blanket transgender inclusion or exclusion” in women’s sports.

The petitions have been signed by some 300 Olympians and U.S. national team members along with 2,500 athletes from the college, club and high school level.

Olympic gold medal swimmer Nancy Hogshead-Makar is the founder of the advocacy group Champion Women, which is behind one of the petitions.

“These are people who are saying from the sports world that they want to affirm fairness as the guiding principle for when you’re thinking about including transgender athletes,” she said.

Naber signed the petition, and doesn’t agree with the NCAA’s decision to allow Thomas to compete in the championships.

“I’m guessing it’s probably because they don’t want to face the public relations backlash,” he said. “Let me be clear, I fully support Lia’s right to identify any way she wishes and will refer to her in the manner in which she prefers. But I cannot say that her competing against [cisgender] women is a fair competition. And I do believe that she has an unfair advantage because of the way she was raised and born. And, uh, those advantages did not disappear with her change of identity.”

Naber is skeptical Thomas’ estrogen therapy is enough to counter the physiology she developed going through puberty as a boy.

One of Thomas’ teammates called the situation “insane” in a recent interview with NewsNation. The teammate accused the NCAA and university of being weak and afraid of cancel culture. She asked to remain anonymous, fearing backlash.

Thomas declined NewsNation’s request for an interview through the university. She recently spoke with Sports Illustrated and pushed back against critics. 

“The very simple answer is that I am not a man. I’m a woman. So I belong on the women’s team,” she said.