The Dutchman, who scored both goals in Sunday's Community Shield victory, disregards odds suggesting that Red Devils are the third-most likely to win the Premier League.
The Dutch striker netted both goals as the reigning league champion topped Wigan Athletic 2-0 at Wembley Stadium on Sunday to lift the Community Shield in David Moyes' official first game in charge.
United has had mixed results during the preseason and is yet to make an impact in the summer transfer window, and bookmakers have named the Red Devils the third favorites for the title behind neighbors Manchester City and Jose Mourinho's Chelsea.
Van Persie does not want to acknowledge those odds, though, as he is confident that the current team can repeat last season's runaway success to retain their Premier League crown.
"It's always nice to score and especially at Wembley. It's a great day for the fans for us and for the manager as well," van Persie told ITV after Sunday's victory. "We've got [Wilfried] Zaha who has done really well and, as I said earlier, I believe in this team.
"I don't want to be funny but we are the champions. So third favorites? Can you explain that? I don't really care. I believe in this team and I believe that we will compete until the end again."
Ryan Giggs was impressed with van Persie's performance against Wigan and hopes the striker can reproduce his 26 goals to fire United to the title again.
"The first goal was a brilliant goal and the timing was brilliant," Giggs said. "It was a great start for us, we hope Robin can reproduce the form he showed for us last year.
"We just know we've got good players in the team. It's always hard when you’re champions, you've got to reproduce the form you showed last year and I hope we do that."