Sir Alex Ferguson has insisted that his Manchester United side can shift up another gear to a higher level as they look to defend their Premiership crown. Chelsea captain John Terry said earlier in the week he feels United have nothing more to improve upon.

"That is a challenge for us," he told the Manchester Evening News.

"With the young players we have like Anderson, Ronaldo, Rooney, Nani there is improvement there. Our players have the capacity to improve. So we'll see.

"I am optimistic because I see no deterioration. We have to protect the dinosaurs a little bit more - Giggs, Scholes and Gary Neville - but they are fit guys.

"Giggs' endurance tests were the best in the club this summer. Unbelievable. He will play a lot of games for us. He is lucky because he has never carried any weight. He has always looked after himself.

"Scholes and Neville are much the same. There's a lot of football left in them. Edwin van der Sar is the normal van der Sar. He is looking fantastic for his age and he is a great example of how to look after yourself and give yourself extra years.

“I am expecting a natural progression from the younger ones. It is the same as what I said about Rooney and Ronaldo last season.

"A year ago I was asked if Ronaldo could score more than 23 goals and I replied that I was looking for improvement.

"Improvement can come in different ways for Ronaldo this season. Forty-two goals is a target, it is still possible for him to achieve it given the talent of the boy and his goal-scoring ability but you have to say it's a big target for him.

"Where you will see the improvement is in his authority and decision-making which comes with experience, which gives you a lot of things, timing especially."