Two Argentinian footballers are leading the way for transgender players.
Marcos Rojo and Mara Gomez feel like themselves when they're out on the pitch in Argentina.
Mara started playing at 15 and now at 23, she plays for a team south of Buenos Aires.
"When I started playing," Mara said, "there was a lot of discrimination, exclusion, abuse, and verbal abuse in the streets and at school."
Mara wants to be the first transgender player in women's professional league.
But her coach at Villa San Carlos club's female team, Juan Cruz Vitale said whilst she's good at scoring goals, she's not the strongest yet on the field.
"The main hypothesis against her participation is that she will be stronger than the rest, and the reality is she is not. I have several girls who are stronger."
Ayelen Pujol, sports and gender journalist said, "The discussion or debate that takes place in high-performance sport, above all, is linked to this tradeoff between the biological and the legal."
Meanwhile, at 20, Marcos plays centre forward for a men's team in the northeast of the country.
He has a lot of support from his family about changing his name and gender on his national identity card.
"If you know how to play ball, that's it," Marcos said, "I think you're not disadvantaged by strength or anything in the world, I mean, it's all based on practice."
Sebastian Rajoy, President of his club at Union del Suburbio football club said the competition is strong for everyone regardless of gender.
"Here the position is not granted to anyone, you have to win it by playing, playing as a team and individually."
Marcos and Mara both know they could have to submit hormone test before they're fully accepted into the leagues, but for now, they're already blazing the trail.