Sunday's game at Emirates Stadium is the clubs' first meeting since champions United mauled Arsenal 8-2 at Old Trafford in August.
Despite that crushing defeat, the North Londoners are still involved in the hunt for a top four finish if not the title itself.
However, asked about the importance of the United game, Wenger told Arsenal Player on the club's website: "It's still the same.
"It is not the only game any more because you have Chelsea and Man City coming in, with Liverpool still there. But it is a game that is watched all over the world."
Wenger said that despite this season's setbacks, he still felt United and Arsenal are at a similar level.
"I still think that when we have everybody available we are a strong force in this league. That's why it is important that we fight very hard not to drop points."
"They sometimes have a very compact midfield to kill our passing game and get us on the counter-attack. They do that very well," he said.
"I believe that sometimes it works for them, although last year we beat them 1-0 in a convincing way. It depends on how well we play on the day, how well we pass the ball through their lines, no matter how many are in there."
Wenger hopes to have defender Thomas Vermaelen back on Sunday, but Thierry Henry, who has played in Arsenal's last two games since resigning on loan, could miss out because of a calf problem.
Vermaelen has not played since limping off early in the second half against Queens Park Rangers on New Year's Eve.
The Gunners' 1-0 win o
