The 31-year-old will go under the knife in Sweden next week after failing to overcome an Achilles problem which had already kept him out of the side for the previous nine games.
It was decided on Thursday that Cazorla needed an operation despite the fact Wenger had said last week he was hopeful the Spain international would be back in contention in a fortnight.
There was more bad news for Wenger, who also confirmed full-back Mathieu Debuchy could be out for six weeks with a "severe" hamstring injury.
That means he is likely to be out until the new year, with Cazorla potentially sidelined until March, but Wenger said he had no doubts that the club had acted in the right way.
Asked if he had any regrets over the treatment Cazorla's injury, Wenger replied: "No I don't because we always liaise with Santi's people and he is treated the way we wanted him to be treated.
"It is always very sensitive
Bone inflammation, you never know how long it will last
For me it's very bad news
You always know the date of the surgery but never the date where the player will play again.
"I always try to put absolutely everything in place to avoid surgery because it creates anxiety and rehab
When you can avoid it, you have to avoid it.
"In this case, unfortunately we have come to that conclusion
Now they tell me that he will be out for two months at least but two months can sometimes be three as well.
"What's going wrong is that he has an inflammation at the back of his foot
Nobody really knows where it comes from because he has been treated against this inflammation.
"The anti-inflammatory injections have not got rid of it
The surgeon decided to have an exploratory surgery - that means open and see what's going on in there."
Wenger has other midfield options and has been trying to find a balance with the likes of Francis Coquelin, Aaron Ramsey, Mohamed Elneny and Granit Xhaka.
And the Frenchman said he will not go looking for a replacement for Cazorla in the January transfer window.
"Not really, no," he said when asked if he would delve into the transfer market.
"In midfield we have many players
There are two reasons - first of all we have the number and the quality and secondly, in the January transfer market, you will not necessarily find a Cazorla, even if you wanted to.
"Santi is desperate to play football
He's only happy on the football pitch
I've spoken to him, of course
He himself wants to get out of that vicious circle of going out and coming in again
He just wants to cure it."
Wenger said Debuchy could miss six weeks after injuring his hamstring just 16 minutes into his comeback.
The France international was a surprise inclusion in the Gunners side that beat Bournemouth 3-1 last weekend despite not having started a game for the club in over a year.
The risk backfired as he limped off early on and Wenger confirmed the former Newcastle right-back faces another spell out.
"It's a severe hamstring injury
Six weeks, I think," he said.
"Look, it's frustrating for me, but even more for him because he fights very hard
He is a guy who has exceptional attitude and is very serious.
"Overall, I think that he is absolutely disappointed, but he is as well a fighter and he will fight to come back."
Carl Jenkinson is Wenger's only fit natural right-back, but he is expected to be dropped for Saturday's trip to West Ham - a club he spent two years on loan at in the last two seasons - with Gabriel likely to deputise.
Olivier Giroud could also miss out with a groin problem, but looks set to be fit to face Basle in the Champions League next week.
Source : PA
Source: PA