Incredibly, United have dropped just two points in their last 25 home games, and they came against West Brom last season after Sir Alex Ferguson's side had got themselves two goals ahead. It is an amazing statistic, dating back to Chelsea's triumph at Old Trafford in April 2010.
Portugal winger Nani said: "City have a fantastic team at the moment with fantastic players. They are playing a lot of good stuff and it will be difficult to play against them. But we should not forget; we are United. When we play at home it is very hard to beat us. That is why we are so confident."
Nani concedes United will be additionally motivated on Sunday, purely due to the nature of the opposition.
At the same time, he does not believe it is either fair or accurate to bill the game as being crucial to the title race as a whole, not when there are so many more matches to face, and other threats lurking elsewhere.
He said: "City are one of the teams who have been doing fantastically well since the season started. Chelsea have been excellent for a start. I just feel it is too early to say it is just going to be about Manchester United and Manchester City for the title."
Yet Nani accepts these games do tend to take on a life of their own, with so much scope for drama and tension.
"These are the games that always get the team motivated," he said.
"When we play these games the team has a different attitude and a different hunger. Everyone likes to play in matches like this one and clearly, we hope to win as well."