Van Persie faces missing the season after undergoing ankle surgery.
Wenger said: When you have such a big surgery there is one thing that is important first of all, and that is the opinion of the surgeon, will he be the player he was before?
"We had a clear answer. 'Yes'.
"The second thing that is very important in the first stage after surgery is has he an infection or not? He hasn't.
"The third thing is patience. At the moment he cannot do anything, he is just sitting at home waiting until he can work again. The first two steps have been very successful."