United face Arsenal on Sunday, trailing the Gunners by eight points and knowing defeat will put them in a precarious position as they look to keep hold of a crown they won by an impressive 11 points last term.
Not only that, it would place a huge question mark over the credentials of David Moyes' team given they collected a solitary draw from the early season encounters with Chelsea, Liverpool and Manchester City that their new Scottish manager was so wary of.
Yet Rooney insists that inside the Old Trafford camp, none of these doubts exist.
The vibe, he revealed, remains that of champions.
"We always believe," he said. "We believe we can go on and win the league.
"We have been in this position before and gone on to win titles so there is no reason why we cannot do it again. We are hitting form at the right time.
"If we can continue that and get to Christmas within touching distance, or maybe even at the top, we will be in a great position."
Rooney was speaking at the launch of a three-year partnership between United and their new official timekeeper Bulova.
As part of the deal, the United squad will get the chance to design their own personalised watch, which Rooney intends to dedicate to his children - Kai and Klay.
Before that though, Rooney and his team-mates have a lot of work ahead of them.
At times this season it has almost seemed like Rooney has been carrying his team-mates.
While so many others, including Robin van Persie, have found life a struggle, the 28-year-old has been on top form.
It made it such a shame for United therefore that he was below peak fitness for those Chelsea and Manchester City games, and in between sitting out the Liverpool encounter completely after having his head sliced open in a freak training ground collision with Phil Jones.
Now Rooney is fully fit, although he is adamant United are no one-man band.
"I hope I can make a difference this weekend," he said. "But we have many players who can win us games.
"It is not about one person. It is about us all working together to get those three points.
"We are starting to adjust to the training and the new ideas from the manager. We are playing a bit better and have been getting good results.
"Overall, we are in a good place. I am sure if we can win on Sunday it will make us even stronger and give us that belief that we can go on."
On Sunday, Rooney says the collective effort must involve the Old Trafford faithful.
Often derided for a lack of atmosphere, the stadium tends to be at its noisiest for the biggest of matches.
For all kinds of reasons, this fixture is among the most important. Rooney just hopes the Red Devils supporters recognise it.
"The atmosphere at Old Trafford for big games is great," he said. "I am sure the fans realise this is a really important match for us and will be at their best.
"When they are like that it brings energy into our play. We will need them this weekend."