The Arsenal and England midfielder will have ankle op tomorrow, the SEVENTH of his career, with the 23-year-old having suffered an amazing 24 injuries.
Wilshere suffered a fracture in training in August, and will have a small plate inserted into his left fibula.
"It's still early in the season and he can be back in mid-December when there is still a long way to play," said Wenger.
"This kind of injury is not a kind that can damage your career.
"It's a bone that needs a little clip in, nothing major. It's not a career-threatening injury.
"I think he's young enough to get over it. And his body will stabilise.
"I'm confident he will and that he can make a career his talent deserves."
But club captain Mikel Arteta admitted Wilshere faces a tough mental challenge when he make his latest comeback.
The midfielder said: "Jack has had a lot of set-backs in his career but he has always shown character and enthusiasm to get back.
"He has an amazing career in front of him. The danger is that he doesn't believe it himself, he doesn't believe his body. He needs to trust himself."
The new blow appeared to knock Wenger's hopes he could lead the north Londoners to a first success in the Champions League and he admitted: "We are ambitious, but we are not dreamers."
The Gunners face Dinamo Zagreb tonight with the home side unbeaten in 41 matches, although they have failed to win their last 15 Champions League group games and have never made the knockout stage.
"The drive to win it is immense," Wenger said.
"It has never been done at Arsenal. We were very close (losing to Barcelona in the 2006 final) but I am long enough in the job to know you have to be realistic."
While Wenger has been having a relatively stress-free time, his bitter rival Jose Mourinho at Chelsea has found himself under immense scrutiny following the champions' shocking start to the season.
Arsenal visit Chelsea on Saturday, but Wenger refused to reveal whether he was enjoying seeing his rival suffer.
"That's part of our job and I wouldn't say much more than that," Wenger added.
"It is important that we focus on our game. In the Champions League you're quickly out if you don't start well."
