Against a sea of red and black flags, an angry throng punches the air and chants, “Go f— yourself!” as police look on. These are scenes not from a protest, but from the march of the Red and Black Bloc (RBB), the fans of Western Sydney Wanderers FC, in Parramatta earlier this year.

The rapid rise of the A-League soccer club, who in 2014 became the only Australian side to win the AFC Asian Champions League, is the subject of SBS documentary Came from Nowhere.

Socceroo turned broadcaster Craig Foster has a theory about why the film, in which he appears, is screening now. “The club is facing great challenges, as is the game itself, in terms of financial sustainability,” says Foster.

“That may be why this documentary is well-timed because it gives fans an opportunity to look back on what was possible, and continue to dream that the game can one day be representative of the passion of the people that follow it.”

That passion attracted negative press for the Wanderers from the start. Last month, a supporter received a two-year ban from Football Australia for allegedly performing the Nazi salute at the Sydney derby. But while Foster opposes antisocial behaviour, he believes an overreaction by police, media and game authorities, has dampened enthusiasm.

“The fans felt let down by the game,” he says. “In Europe, thousands of people stand together and sing and joke and experience the game in that way, and as football people, we love that. At Western Sydney Wanderers, they wanted to bring back football culture in Australia … when tens of thousands of Wanderers fans started to walk to games in groups, some people were challenged because they’d never seen it, and so they equated that with danger and fear. I think there are lingering impacts of that across the game.”

The documentary hears from players, journalists, police and fans, including retired high school principal Judith O’Brien, Chilean Australian Pia Herrera, a “la banda” drummer, Iraqi-Assyrian refugee Tatiyana Shaba and former Croatian professional footballer Harry Karl, who received a (since overturned) lifetime ban.

Wanderers ambassador Ian “Dicko” Dickson, who also appears, grew up in the UK barracking for Birmingham City (despite being named after his grandfather who played for rival team Aston Villa). The former Australian Idol judge was shocked when he first heard the racist Australian slur for soccer.