Wayne Rooney believes Arsenal's title credentials should not be judged until later in the season, despite their strong start.
Arsene Wenger's men are unbeaten since the first day of the season and have opened up a five-point lead at the top of the division.
Yet Rooney, whose Manchester United side have made a faltering start to life under David Moyes, has stressed there is a long way to go, and that the real challenge for Arsenal will be staying at the summit.
"We'll have to wait and see where Arsenal are in March," he said. "We've seen before that they've been in the top two until February or March and then faded away.
"They are doing brilliantly at the minute, so it's down to them to try and stay there and us to catch them."
Rooney is confident of picking up three points when the sides meet at Old Trafford on Sunday.
"We're obviously capable of beating Arsenal," he continued. "We've done it many times in the past.
"They're on a good run of form at the moment and they're top of the league, so we know it's going to be a difficult game.
"But we have to go into it with confidence and a belief this is when we can edge closer to them and bring us back into the mix of being at the top of the league.
"There are only nine or 10 games gone, so there's no big worry at the moment.
"We're starting to do well. We're confident at the minute; we're getting more clean sheets and playing with freedom.
"If we can get the victory on Sunday then we're in a great position."
Rooney has scored seven goals in all competitions for United this season.comments