Last year they wore rainbow laces and now Sydney FC will step up their Mardi Gras support by walking onto the pitch behind a sea of rainbow flags.

The Sky Blues will be the first club in A-League history to promote LGBTIQ inclusion at a professional match when they take on Melbourne Victory in Friday night's Big Blue, a day before the Sydney Gay and Lesbian Mardi Gras Parade.

They will be led onto the field by players from Sydney Rangers FC, Australia's first football club for gay men, and The Flying Bats Women's FC, the world's largest lesbian football club, carrying a large rainbow flag and waving eight smaller flags.

Sky Blues captain Alex Brosque said raising awareness was an important step in tackling discrimination in football.

"We have a multi-cultural and diverse community and supporter base at Sydney FC and we are committed to welcoming everyone into the Sky Blue family and to our games," he said.

Sydney FC players will wear rainbow laces in their boots and 2,000 laces will be handed out to the crowd before the match.

Sky Blues chief executive Tony Pignata said he hoped other A-League clubs would follow their initiative.

"The Sydney FC family is inclusive of everyone and we do not discriminate on account of gender or sexuality," he said.

Friday's match comes two weeks after Western Sydney Wanderers supporters were condemned for a homophobic banner depicting a blue-faced male, suggested to be Sydney FC coach Graham Arnold, engaged in a sexual act.

Fourteen members of the Red and Black Bloc had their Wanderers memberships suspended and the FFA fined the club $20,000.

Sydney Rangers president Joseph Roppolo said he hoped the sanctions would send a strong message, but unfortunately the club had still received homophobic and hateful comments on social media this week.

"It's clear we have a lot of work to do to change homophobic attitudes which are surprisingly still common and accepted as normal in sporting culture," he said.

"We deeply appreciate this latest support Sydney FC is showing to our community."

AAP