Sir Alex Ferguson has promised to hand Rooney a more central striking role for the champions after Ronaldo made the switch to Real Madrid.
The England man was regularly dispatched to the flanks to accommodate the Portuguese last season but still notched 20 goals for United.
And Rooney is convinced he can better that in 2009/10. "Of course 25 is a target which I hope I'm going to reach," said Rooney. "I've always said I should score more and hopefully I'll do that this season.
"I've got what I wanted. I like to play through the middle. The manager has come out now and said I am going to play there throughout the season so I'm delighted with that. He may change his mind and whatever he says goes, but I hope he will play me there for most of the season. If I keep scoring goals I will justify it."
He added: "I am comfortable with the extra responsibility now Cristiano has gone. There have been big expectations on me for the last seven years so whether he was here or not I would still have that.
"But I have never looked at myself as being the main man. It is a team game. I won't win a trophy on my own."
Rooney has also backed strike partner Dimitar Berbatov to shine after he had a quiet first season at Old Trafford: "You can see in training and games during pre-season that Dimitar has looked sharper," said Rooney.
"He looks like he is more determined. He is tracking back with the full-backs in pre-season and is definitely working harder and trying to impress. He is a brilliant player. He has so much quality he has got and we all want him to show it."