The Gunners are set to face off against their former captain for the first time since his £24million summer move to Old Trafford on Saturday lunchtime.
Van Persie netted some 132 goals in eight seasons with the north London club - including 37 last term to help drag them into third place in the Barclays Premier League.
Wenger is all too aware of just what a threat the "exceptional" Dutchman can be, having seen him score seven Premier League goals for United already.
"Robin Van Persie has a great quality in the fraction of a second that he understands where to go - you can talk and talk and talk, but defenders have to read that at the same time," said Wenger.
"His speed of analysing those little pockets around the box are absolutely exceptional.
"The team know him as well because they have played against him in training.
"But in the game it is a question of timing - how quickly will they read it as well as he reads it?"
The Gunners were humiliated 8-2 on their last visit to United in August 2011.
However, they were crippled by injuries to key men for the game, in which then rookie full-back Carl Jenkinson was sent off, with Aaron Ramsey the only likely starter tomorrow from the XI that miserable afternoon.
Wenger insists while painful at the time, that freak result under "exceptional circumstances" following an energy-sapping Champions League qualifier in Udinese is now well and truly out of the squad's system.
Nevertheless, the Arsenal manager insists damage limitation was never part of his footballing psyche.
"There is purely an emotional aspect in the 8-2, but there is no mathematical consequence. We lost a game, that is all," he said.
"The football aspect was easy to explain. We gave everything in Udinese three days before in 35 degrees at night and I knew that we would be dead.
"We lost vital defensive players in that game. We went out very exposed, but the most important game of the week was at Udinese."
Wenger recalled: "With 20 minutes to go at Old Trafford, it was 4-1, and I decided to try to come back with 10 men and we were already dead.
"Of course after that we paid for it, so maybe I should have kept it tight and go out with 4-1 and say 'thank-you very much, see you next week'.
"But I want to do what gives us the best chance to win games - when you make teams, you cannot go against nature.
"You cannot play with (Jack) Wilshere, (Santi) Cazorla and (Mikel) Arteta and say 'look, we only defend'. They would say 'what are we doing on the football pitch then?'
"Somewhere your style is dictated by the players you pick.
"Sometimes you are right when you don't win, but also sometimes maybe you have to learn not to lose first before you can win a game, you give a bit more security to the team and I have done that as well.
"But still our basic philosophy is to go forward and attack."