SIR Alex Ferguson has delivered a worrying message to the title rivals who feel they have seen the best of Wayne Rooney and Cristiano Ronaldo - "You ain't seen nothing yet."

The duo have long been thought of as two of the most promising young talents in the world and scored 23 goals each as United stormed to their ninth Premier League crown.

Ferguson acknowledged they could buck the trend of when players reach their peak but, as his side prepare to begin the defence of their title against Reading on Sunday, he has no hesitation in outlining his belief both players can deliver even more.

"There is no doubt Rooney and Ronaldo can do better," he said.

"As a player, I felt at my strongest when I was 25 and 26, so they have another three years or more before they get anywhere near their peak and maturity.

"At 21, you do daft things on the pitch. You produce moments of ability but there is no consistency. You might score a goal, then miss one.

"Maybe these two defy that a little bit but experience gives you authority, timing and control."

During pre-season both players have shown glimpses of hitting form, with Rooney in particular impressing.

The England star has been on the verge of losing his temper on occasion too, notably in Sunday's Community Shield win over Chelsea when he ranted at what he felt was an unfair booking for a foul on Petr Cech.

Tirades

Ferguson accepts such tirades are not always desirable but the Scot recognises they are part of Rooney's make up and he is not about to do anything that could diffuse the striker's spark.

"He will always have that," Ferguson added. "Wayne knows when he has done wrong, so when he is unfairly treated he reacts to it.

"You don't want him to do that all the time but at least there is an honesty about what he does."

With Nani and Anderson likely to start on the bench, Louis Saha injured, Alan Smith and Giuseppe Rossi sold and Carlos Tevez yet to complete his switch to Old Trafford, Rooney is likely to be the only orthodox striker in Ferguson's starting line-up this weekend.

Yet, far from getting frustrated at the continued delay over Tevez's arrival, the United manager is happy for the Premier League to scrutinise every aspect of the deal.

And, having watched the Argentina forward in training this week, Ferguson is convinced the 23-year-old is fit enough to feature against Manchester City on August 19 providing the relevant paperwork has been completed.

"Carlos has surprised us," he admitted. "We thought he would need more training but he looks in great shape.

"I am happy with what the Premier League are doing because eventually we will get a player in the right circumstances, with everything clarified and cleared by the appropriate authorities.

"It is a difficult situation to assess because a derby game can be frenetic. Once we know he can play, we can make a decision quite easily."

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