Fired-up Sydney FC coach Frank Farina has hit back at trolls who he says have hurled "mistruths, abuse and personal insults" at him and his struggling A-League team.

Farina, in his first personal blog entry in more than four months, said he had spent some time thinking about "the new player in the game" - social media.

Frank Farina has responded to Twitter abuse via a blog entry. Credit:Getty Images

"As I've said many times before, I don't mind if people have a different opinion or question mine. Many people do," the former Socceroos coach wrote.

"But I do have a question for the small group of people - who mostly hide behind fake names or no name - who hurl mistruths, abuse and personal insults at me, some of the staff and the players. Are you really real football fans?