(Adds detail on Obama, picture available)
By Daniel Wallis
PHOENIX, Jan 30 (Reuters) - As fans gather for Sunday's Super Bowl in Arizona, a billboard campaign is seeking to win acceptance for gay players whom the organizers say have been part of the National Football League since it started, but are scared to come out in public.
The campaign by SCRUFF, a gay social networking application used by 7 million people worldwide, features two men eyeing each other in a locker room alongside the slogan "Play On Our Team."
At a time when NFL players such as Michael Sam and Kwame Harris have come out in public, the organizers say they want to use the Super Bowl - the biggest annual U.S. sporting event with an estimated global TV audience of 100 million people - to create a dialog about acceptance in professional sports.
SCRUFF founder Johnny Skandros said he wanted to highlight the fact that gay men have always played on football teams, and that they don't fall into simple stereotypes.
"I think that people like Michael Sam, Kwame Harris and Jason Collins didn't only make it OK to be an openly gay sports player, they also made it easier for gay sports fans to feel a full part of their hometown team," Skandros told Reuters.
"This ad is a nod to them, to those trailblazers."
Sam, the first openly gay player drafted by an NFL team, told Oprah Winfrey last month he is far from the only homosexual in pro football, and that he was surprised others were not inspired to come out after his announcement.
Sam revealed he is gay in February 2014 and was picked by the St. Louis Rams in May. The Rams cut him in August, but he was then picked up by the Dallas Cowboys practice team, only to be cut again last October.
Sam told Oprah he had heard from a few gay players who privately thanked him for his disclosure, and told him they wished they had that courage.
U.S. President Barack Obama praised Sam's bravery at the time, a White House spokesman said, and believes his action was an important step forward.
"Regardless of sexual orientation, everybody on a sports team is playing to win, and we're saying we invite everyone to play on our team," Skandros said. "It's a message of inclusiveness ... The NFL should recognize that gay men have been playing in the league since the very first Super Bowl." (Reporting by Daniel Wallis; Editing by Sandra Maler)