But as a gay woman, she also felt burdened by a policy written into the student handbook at her private Christian university, which banned homosexual behavior and advocacy for LGBT issues, she tells PEOPLE exclusively for a portfolio of gay professional athletes who discuss their decision to play and live openly. Watch a video of all the athletes below.
"I definitely wasn't hiding who I was at Baylor," she says. "It was never an issue to feel rejected by my teammates. They were definitely understanding and welcoming with me being who I am. The coaches were, too."
But after being out to friends and family at home in Houston from the age of 15, Griner, now, 23, says the school's official stance – which she didn't discover until the start of her sophomore year – caused tension, especially when a coach called Griner into her office after she sent a Tweet to her then-girlfriend.
"Other players, they can go out on Valentine's Day with their boyfriends and it'd be no problem," she says. "I go out with my girlfriend, I'm getting a phone call, 'Brittney, what were you doing on Valentine's Day?' I had to take my Tweet down. I was like, why do I have to take my Tweet down when my teammates don't have to take theirs down?"
"It definitely felt like there was a double standard."
After deciding to go public with the 2013 WNBA draft, and in a new memoir, In My Skin, Griner says she's put her suppressed identity behind her.
"People tell me I'm going to break the barrier and trailblaze. I just kind of look at it like, I'm just trying to help out, I'm just trying to make it where it's not as tough for the next generation."
She also hopes someday to help reverse the policy at Baylor, a school she still loves. "To break something, we have to bring it up, we have to get it out there, and eventually the topic will start to become more of a conversation," she says.
For more on Brittney Griner and the exclusive portfolio of gay professional athletes, pick up this week's issue of PEOPLE, on newsstands now.