Following the arrival of Robin van Persie from Arsenal, Blues manager Roberto Mancini reiterated his belief the Red Devils are favourites to take away the crown his own side won so dramatically in May. Ferguson just scoffs at the suggestion, as he does with Mancini's claim that United are the ones with the best array of strikers.
"We are favourites every week according to him (Mancini)," said Ferguson. "Is he ever going to realise he has got a decent team himself? Our biggest threat this season are Manchester City."
He added: "Chelsea have won the European Cup, which is the trophy Roman Abramovich has been after. Now he has got excited again and loosened the purse strings to sign a few players.
"I am almost certain they will be challenging. But I look at Manchester City as our biggest danger."
Van Persie goes straight into Ferguson's squad for Monday's trip to Everton, even though he is likely to start on the bench due to a lack of recent match practice.
However, the United boss is just delighted to have snared his number one summer transfer target, who at the end of last season, he felt there was no chance of landing.
"We never thought we could get Van Persie," said Ferguson. "I thought Arsenal are not going to let him go.
"When I read he had refused a new contract that is when we acted. It has been a long haul and he (Wenger) got a great price - he could win a poker school in Govan. But we are happy the matter is concluded."
A cynic might suggest Ferguson went for Van Persie because, having celebrated his 70th birthday, the United boss simply does not have the time to wait for a new team to emerge as bona-fide challengers to City.