Richards insists City are ready to shrug off their noisy neighbours tag and build on their FA Cup success from last season.
"United now know, much as they won't say it, that we are a genuine threat to them," the 23-year-old defender told the Manchester Evening News. "To get that banner down is quality - we have got the last laugh.
"We are not going out and saying we will win this game or that game, but they call us the noisy neighbours. I think they're a bit frightened."