Football legend Neville Southall is "certain" he played with gay footballers as he criticised the sport's authorities for not giving the issue enough support.
He called on the FA and top flight clubs to be "more proactive".
Southall, 62, said: "The number of footballers there are, there are some gay footballers in there. There are probably some gay football staff members too.
"The number of players I played with, I'm sure I had some gay teammates.
"We should be ashamed in the football community that players don't feel able to come out.
"I think the first one that comes out would open the floodgates. If he was an Everton player he would have 40,000 people on his side and probably supporters of all the other clubs too.
"Anyone who was homophobic would be shouted down. I think it would be about 95% positive."
There is yet to be a Premier League player who has come out during their career, although former Aston Villa, West Ham and Everton midfielder Thomas Hitzlsperger announced he was gay after retirement.
Tragic Justin Fashanu is the most famous footballer to come out. Southall revealed one of the worst moments of his career was when Everton played Fashanu's Hearts in a friendly and the troubled star, who later killed himself, was subjected to vile abuse from the crowds.
Former goalkeeper Southall said: "It was horrendous. The atmosphere around the grounds was probably a lot more aggressive than it is today, a lot more macho."
Southall was regarded as one of the greatest goalkeepers of his generation during a glittering 17-year spell with Everton.
But these days he occupies most of his time with social justice issues than the beautiful game and called on the footballing authorities to stop "paying lip service" to the problem issue of homophobia in football.
He wants the FA to go public with what the protocol would be for a player who wanted to come out so they know what to expect.
Southall refuted the suggestion that a Premier League dressing room would be a difficult place for a gay player, insisting that players would "rally around" and "stick together".
He said: "I'm convinced the dressing room would rally around anyone who came out like that. Each dressing room has a siege mentality and you stick together. You look after one another.
"It is what it is. In our dressing room if someone was gay or had three heads it wouldn't have mattered, we would have judged him on his playing and if he was of value to the team.
"Clubs want their players to play to their full potential. Surely players can't play to their full potential if they can't be themselves?"
An FA spokesman said: "Coming out, irrespective of gender, is an individual and personal decision. We will always offer the full support of the FA to anybody that chooses to come out.
"We continue to work with our partners across the game to help create a safe and supportive environment for any player to come out if they wish to do so. We are committed to working with these partners to encourage fans and players to report abuse, both at a national and county FA level, and work with the leagues, campaign groups and the statutory agencies to sanction and educate perpetrators."
A Premier League spokesman said: "Premier League football is open to everyone and our clubs continue to work together to create safe and welcoming environments for all of our fans, players and employees.
"Through our long-standing partnership with Stonewall we continue to celebrate and promote LGBT inclusion and have worked together to improve policies and practices, including reporting measures, pastoral care and staff training.
"Our clubs work hard to promote equality and diversity in everything they do, from the atmosphere and experience in their stadiums to the many projects they run in their communities.”
Mind Games: The Ups and Downs of Life and Football by Neville Southall (HarperNonFiction, £20).