"Alone in the Game," a new documentary about elite LGBT athletes set to debut June 15 at the AFI Docs Film Festival in Washington, poses an interesting hypothetical.

"What if," ESPN commentator LZ Granderson says, "the next LeBron James is even better, but he might be gay. Are we going to miss out on seeing a great athlete because of homophobia? I sure hope not."

The powerful trailer for the documentary packs a lot into two minutes, but the film's creator and executive producer, Dan McFarland, told USA Today that the athletes' stories are notable not because they're out as gay and lesbian athletes but how many more like them there could be and should be, if not for prejudices in society.

“The idea was to create a documentary that investigated the real-life stories of elite LGBT athletes,” he says, “delving deep into the big business of sports and providing an inside look at the secret lives of closeted athletes and exposing a culture of exclusion, bigotry and discrimination, which really keeps these athletes in the closet and living in secrecy and in silence.”

Case in point, according to USA Today, is the Division I player in the film who has been told he has a shot at the NFL. His face blurred and voice altered, he says he fears that if he were to come out that teammates wouldn’t talk to him and coaches would see him as inferior.

“I’m not ashamed,” the player says, “just scared.”

That kind of emotion and frustration, sadness and anger spring from scenes from the film that are part of the trailer.

"I just wish you guys would see me as Michael Sam, the football player, instead of Michael Sam, the gay football player," the former Missouri football player tells the media at the NFL Scouting Combine.

“If there wasn’t homophobia in sports, and if everyone felt comfortable in being who they were,” U.S. women’s soccer star Megan Rapinoe says, “then everyone who is gay would be out.”

"I'd always planned on killing myself when I was done with football," former NFL offensive lineman Ryan O’Callaghan says. "I thought I'd rather be dead than an out gay man."

"I felt like the only option," former Arizona and Pepperdine basketball player Layana White says, "was to just take my life."

Here’s a first look at the powerful trailer for the feature-length film that will run on AT&T Audience Network at 8 p.m. ET June 28.