Manchester United manager Sir Alex Ferguson insists Wayne Rooney still has plenty to learn before the forward reaches his peak.
The 23-year-old is rated among the best players in the world, but his boss believes he still needs to develop his game.
England will be looking towards Rooney as they go in search of success at the 2010 World Cup, however, Ferguson is keen not to place too much pressure on the youngster.
"There will be an expectation about Wayne Rooney this season purely because he is English," said the Red Devils chief.
"Without question he is the main striker that England's hopes will be pinned on at the World Cup, so that is where the expectation is all coming from.
"But I would like to see the boy develop his game in a lot of departments.
"He is 23 now. You will get the maturity when he gets to 25. Then there will be a more consistent nature to his game."
Ferguson has also brushed off Rooney's angry reaction to a penalty box clattering in a pre-season friendly against a Malaysian XI on Monday.
"He got a bit annoyed because the goalkeeper caught him on the ear that has been stitched," said the Scot. "It was a momentary explosion of anger."