Rooney has been in phenomenal form for Manchester United this season and took his tally to 32 goals with another brace in yesterday's 3-0 win over Fulham at Old Trafford.

It took United back to the Premier League summit and once again led to a glut of plaudits for the 24-year-old, who it is now generally accepted has gatecrashed the trio of Lionel Messi, Cristiano Ronaldo and Kaka who were regarded as the best three players on the planet.

Having worked alongside him at close quarters since his own club record £30.75million move from Tottenham in 2008, Berbatov knows exactly how good Rooney is.

And the Bulgarian has no hesitation in declaring the striker his number one.

"At the moment he is the best in the world," said Berbatov.

"He is still so young and has the chance to be even greater.

"Like I have told him many times, he just needs to stay healthy and he can achieve everything."

Berbatov certainly sees no reason why Rooney should fail to crash through the 40-goal barrier given United have eight league games and up to five Champions League matches left this season.

"Wayne can go over 40 because there are plenty of games left in the season," said Berbatov.

"I wish him luck and we are all going to help him to over the 40 mark."

Berbatov took his own tally to 10, all of which have come in the Premier League, which makes him United's second highest scorer, even if he is way adrift of Rooney.

Not that the 29-year-old is bothered about that.

He got as much satisfaction from the goal he created for Rooney yesterday as the one he scored himself.

"If we win it doesn't matter who scores for me as long as we are champions in the end," said Berbatov.

"I try to assist more. In fact I preferred the second assist I gave to Wayne. That is sometimes better than scoring."