Ever since Cristiano Ronaldo's world record departure in 2009, Rooney has carried the burden of leading United's attack.
At times it has seemed like the 26-year-old is doing the job single-handedly.
Ahead of Monday's visit to former club Everton, Rooney insists Van Persie's £24million transfer to United will not lessen the weight of expectation on his shoulders.
However, after losing out on the title to Manchester City on goal difference last term, the Red Devils favourite hopes Van Persie will quickly find the form that allowed the Dutchman to edge Rooney out from the Golden Boot prize last term.
"We are playing for Manchester United, so there is always expectation on us," he said.
"Over the last two or three years I have been the one scoring the goals but that will not happen without the players to give you the assists.
"The only thing that will change is that we might be able to share the goals out a little bit more.
"It would be great for us to score more goals because effectively, that is what we lost the league on last season."
Sir Alex Ferguson will hope there is no negative aspect to Van Persie's transfer and that Rooney responds to the knowledge his status as United's main man is under threat.
Having sat out England's friendly win over Italy in midweek, Rooney looks fresh and ready for the challenge of overhauling City.
And he admits Van Persie's presence in the United dressing room has given everyone a lift.
"Obviously it is great for the team - for the players and fans - to sign a player of his quality," he said.
"As forwards it is great for us to have someone like that to play with and it is always exciting when you sign a new player of that quality and ability.
"It also provides strong competition.
"We are all fighting for one or two places, which is good for the team as a whole."
At roughly the same time as Rooney was speaking, Dimitar Berbatov wandered past, cutting a largely forlorn figure as his Old Trafford career continues to tumble rapidly downhill.
Arguably though, Danny Welbeck is the player who has lost most.
After all, following his performances at Euro 2012, when he seemed to be confirmed as Rooney's first-choice England striking partner, Welbeck might have expected to enjoy similar status at United.
Instead, he finds himself relegated to third, potentially fourth depending upon how United's other significant summer transfer, Shinji Kagawa, is viewed. And all before a lucrative new contract has been signed.
Ferguson has attempted to quell any disquiet from the Welbeck camp by insisting the 21-year-old has a big future.
"Danny is 22 November," said Ferguson.
"As we know he has had growth spurts for the last few years and misses parts of seasons because of the little niggles he gets.
"He will still get little strains every now and then but when he has completed growing and is 23 or 24, he will be a fantastic player.
"He will learn from playing with Robin and Wayne Rooney and Javier Hernandez.
"We have a great combination of strikers now and that encourages me.
"It will be difficult for me but it is better that the whole team enjoys success because we have added another great player rather than worrying if they are going to play or not.
"They have to share in the way forward."
Rooney has an excellent goalscoring record in tandem with Welbeck.
Now he must do the same with Van Persie, although, after what will be only three training sessions together, he emphasised the work that will have to be done.
"Over the next few weeks, we will have to try to get that understanding," said Rooney.
"Hopefully it will come quite quickly and we can form a good partnership.
"You want to get out there training and we are all looking forward to that first game on Monday."