United top the table on goal difference from neighbours Manchester City, with the pair having scored 33 goals between them in four wins out of four. Chelsea are third, two points behind.
"At the moment of course the Manchester teams are enjoying the publicity of the predictions that we're going to be involved in winning the league," Ferguson, a master of pre-match mind games, told a news conference on Friday.
"But then in the background lurks Chelsea and they don't need the publicity because it's all going to Manchester and they will be enjoying that at the moment. But they will be there at the end of the season, there is no doubt about that."
Ferguson praised 33-year-old Chelsea boss Andre Villas-Boas for his start at the club, drawing parallels with his own experience of taking the helm at United nearly 25 years ago.
"The new coach Boas has started very well for a young man that has come to Chelsea, it's a great challenge, it's a hard challenge at his age but he seems to have acquitted himself very well and his team have responded," the Scot said.
"There are similarities when I came from Aberdeen, I had achieved something [Scottish league title], so that helped me and the same for Boas, he won the double [with Porto] last year.
"That is a help, the achievement will stand him in good stead in terms of the start to his time at Chelsea.
"After that the pressure the players will get in terms of his knowledge of the game and his man-management skills is all in the future. He's had a good start."
Ferguson was relieved to come through Wednesday's 1-1 Champions League draw at Benfica with no new injury concerns, meaning only defenders Nemanja Vidic and Rafael, midfielder Tom Cleverley and forward Danny Welbeck remain sidelined.
"We have a strong squad for Sunday which will be a fantastic game," Ferguson said. "The games between both clubs over the last seven years have been very very close affairs... it will be very tight on Sunday again. It should be a good game."
Chelsea were the last team to win at Old Trafford in April 2010 and will be hoping for a repeat in Sunday's match which pits the champions against last season's runners-up.
Last season United dropped only two points at home on their way to a record 19th league title.
