Wilshere impressed in the Champions League rout.
Wenger said of Wilshere's spell at Bolton Wanderers last season, "It was important because it accelerated his career by being confronted in the Premier League and having tough games.
"But, of course, Jack has been educated here and he was already an outstanding player when he left for Bolton. But this is the final part of the education of a player - to be integrated into the first team and play under pressure. That was important for him."
And on if he expected Wilshere to play a central role so early in the season, Wenger added: "Honestly, no. But football teaches you one thing - be open-minded and never have a definite opinion. You need to have opinions sometimes but you always have to have an open mind on players because you can never predict how quickly they develop."