Sir Alex Ferguson has cranked up the pressure on Liverpool manager Rafael Benitez by declaring Chelsea to be the biggest threat to Manchester United's dream of an unprecedented fourth consecutive Premier League title.

Big things are expected of Liverpool this term after their most consistent top-flight campaign since 1990.

Yet Ferguson does not see the Merseyside giants making the improvement necessary to end their championship drought.

"Liverpool had probably their best season for 20 years and still finished four points adrift," said the Scot.

"It will be hard for them to match last season, let alone improve on it. Other teams will know more about them, so it has to be Chelsea as the main threat."

Benitez is bound to bristle at such comments, although with Xabi Alonso joining Cristiano Ronaldo, Kaka and Karim Benzema at Real Madrid, it is difficult to see how a Liverpool side whose focus continues to be the axis of Fernando Torres and Steven Gerrard can get better.

The arrival of Carlo Ancelotti also brings an unknown dimension to Chelsea, although Ferguson believes the Italian's past record makes him an opponent to be respected.

"Ancelotti will play the Milan way," said Ferguson.

"It brought him two European Cups - it should have been three because they should never have lost to Liverpool, so why should he change?"

That put-down of Benitez's proudest moment as Liverpool manager from Istanbul in 2005 will not endear him to the Anfield club either.

Talking about his own club, the United boss insists there is little point attempting to find a like-for-like replacement for Ronaldo, adding that his squad is good enough to cope.

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"People have misread our situation and underestimated our ability to improve players," he said.

"We are expecting a lot from Jonny Evans, Danny Welbeck, Darron Gibson, Federico Macheda and the Da Silva brothers (Rafael and Fabio), while Nani and Anderson will improve this season.

"We will miss Ronaldo's goals, that is obvious.

“But Berbatov will do well this year and Wayne Rooney and Michael Owen are both capable of getting 20 goals."