• 'It has to be Chelsea as the main threat' says Ferguson • 'We knew we could never replace Cristiano Ronaldo'

Sir Alex Ferguson has effectively written off Liverpool's title chances and said that he sees Chelsea as the main threat to his hopes of winning the Premier League for the fourth year in a row.

The Manchester United manager does not believe the impending departure of Xabi Alonso to Real Madrid will affect Liverpool, saying that Rafa Benítez's team are far more reliant on the input of Steven Gerrard and Fernando Torres. But he sees little chance of the squad at Anfield improving on last season's second place.

"Liverpool have just had probably their best season for 20 years, finished up with 86 points and still finished four adrift," he said. "It will be hard for them to match that, let alone improve. Other teams will read Liverpool better."

He is more concerned by Chelsea, who have a new manager in Carlo Ancelotti, the winner of two European Cups and a Serie A title with Milan. "It has to be Chelsea as the main threat," he said. "Ancelotti will change the way Chelsea play. There is plenty of flexibility in what he's got and he should get goals from Didier Drogba and Nicolas Anelka.

"They will play the Milan way. It brought him two European Cups – it should have been three because they should never have lost to Liverpool [in the 2005 final]. So why should he change?"

Ferguson admits United will miss Cristiano Ronaldo, who has joined Madrid, but has backed his young players to shine and help make up for the winger's absence.

"We knew we could never replace Ronaldo," he said. "No matter what anyone says about the lad, for me he is the best footballer in the world. When you've had someone who is the best at what he does, it is no good trying to find someone to do the same job.

"And when you know you can't replace someone or something, you look for a different way. People have misread our situation and they have underestimated our ability to improve players. That is an area where we have proved successful in the past.

"We are expecting a lot from [Jonny] Evans, [Danny] Welbeck, [Darron] Gibson, [Federico] Macheda and the Da Silva brothers. And Nani and Anderson have already shown good things but they will improve next season."