More than half of the 20 Premier League clubs have signed up to the 'Football v Homophobia' campaign.
Eleven clubs - Arsenal, Aston Villa, Chelsea, Crystal Palace, Everton, Liverpool, Manchester City, Manchester United, Stoke, Sunderland and West Ham - have joined the campaign but so far only 16 of the 72 Football League clubs have done likewise.
The month of action was launched at Selhurst Park last weekend, where West Ham's players donned 'FvH' T-shirts.
Hammers skipper Kevin Nolan said: "For us as players and role models, we all recognise the importance of the Football v Homophobia campaign.
"We're passionate about supporting this and we hope that it sends out a message that there is no place for discrimination in football, nor in any sport."
There are no openly gay players in English professional football - former Aston Villa midfielder Thomas Hitzlsperger has come out but only after he had retired from the game.
Sports minister Helen Grant has backed the campaign, saying: "Football v Homophobia is raising the awareness of important issues and provides ways for everyone in football to get involved.
"We hope everyone in the game will continue their support by taking action with the campaign."
Campaign director Lou Englefield added: "This isn't just about players coming out. It's about all of us - including heterosexual players and fans who attend matches week in week out - being willing to speak out and take visible action to challenge prejudice in the game."