United could stretch their lead at the top of the Premier League to 15 points if they defeat QPR on Saturday, but City boss Roberto Mancini believes their neighbours could still suffer a late season slump.
United blew an eight-point advantage in the space of just six matches last term which opened the door for City's dramatic title triumph, but Ferguson feels the champions will also stumble again before the end of the campaign.
"They are going on about us dropping points - but I would say the same thing to be honest," said Ferguson.
"The fact of the matter is they will drop points too. It is unavoidable.
"Teams drop points. It is a tough league. It is not easy winning all your games.
"At the moment we have a good momentum. The only thing we can do is try to win our next match and see where it takes us."