Wenger wary of threat posed by Van Persie
The Netherlands striker moved to Old Trafford from North London in 2012 and won the Premier League title in his first season at the club, but United have struggled since David Moyes replaced Alex Ferguson..
However, Wenger knows his former frontman could come back to haunt the Emirates Stadium outfit on Wednesday when Arsenal attempt to bounce back from a 5-1 humiliation at Liverpool at the weekend that saw them drop down to second in the table behind Chelsea..
"Van Persie is a great player," he said. "It's down to how well we defend against him tomorrow
"I think the Liverpool game was an accident and we want to treat it like that
"We will respond tomorrow (Wednesday) in a very positive way, I'm convinced of that. We know our form at the Emirates will be decisive.
"We've been very stable until now defensively, we have to consider how well we have done until now."
Arsenal have not won a major trophy since 2005 and Wenger believes his players deserve to end the club's trophy drought following their exploits so far this season.
"Winning the Premier League will be a big achievement when we do it but we have a long way to go," he added. "We tend to forget how good we are when you are not successful.
"We have worked very hard until now. These players deserve success"
Manchester United were 1-0 winners when the two sides met at Old Trafford back in November.