The England international has admitted that losing the Premier League title to rivals Manchester City in last year's campaign was a "bad feeling" and is ready to take the trophy back.
The Red Devils are 15 points clear of City at the top of the table with eight games left to play.
"To lose the league in the last second [last season] was a bad feeling," Rooney told the Daily Mail. "But when you're at a club like United, you have to be full of motivation and desire to win every year.
"That comes from the manager and all the players are aware of that. The club and the players have to be full of that desire and that's why the club has been so successful.
"One bad game and everything could fall and so we go out and play each game with a positive attitude. You have to stay focused. You have to make sure that we keep doing our job and keep are concentration."
United can stretch their lead to 18 points if they secure a victory over City in tonight's Manchester derby.