The Gunners will come up against their ex-skipper in Sunday's Barclays Premier League trip to Stamford Bridge after the Spain international signed for the Blues ahead of the World Cup.
Arsenal held first option on the 27-year-old, who left to rejoin his boyhood club for £30million in August 2011 having come of age under Wenger's guidance after arriving as a raw teenager.
Wenger, however, insists all of that is now water under the bridge.
Asked whether he believed Fabregas' first choice would have been to rejoin the Gunners, Wenger said: "Certainly, yes
(But) I don't want to make a big story of that because you have to accept that once he had moved away from us, and it was the first separation which was difficult for us.
"Once he went to Barcelona, he could have gone anywhere else after.
"I personally believe that deal (with Chelsea) was done a long time ago, early 2014."
Wenger continued: "I didn't speak to Cesc directly
I was informed that he might go to Chelsea, but when I was informed I thought the deal was already done.
"Everybody has the freedom to go where they want
We have to respect their decisions.
"As long as we are not in contention (for the transfer), we cannot stop people going where they want.
"I have also told you before why it was not a subject for us - we were in search of more up front and more defensive opportunities than creative midfielders
We have many.
"When Cesc left we bought Ozil to buy an offensive player
We have Cazorla, we have Wilshere, we have Ramsey, we have Oxlade-Chamberlain, who are all offensive players
We were not in the need to buy offensive players.
"It makes sense if you just look at the balance of the team
I think that was a decision that is easy to understand."
Wenger hopes Arsenal fans will not vent their frustrations on Fabregas and they should only have happy memories
"When Cesc looks back at his career he will find that Arsenal and myself had a very positive impact on his career
Nobody can dispute that," he said.
"After that, I hope that everyone has the feeling we had a positive influence and that he had a great career
That is all you can do.
"I have no personal animosity against Fabregas.
"I wish him well
He is a great player and a person and player I love.
"Once he left us, he left us
We are all professionals and we have to accept that."
Wenger conceded the 6-0 mauling at Stamford Bridge in March - where Arsenal were 3-0 down inside 17 minutes and had Alex Oxlade-Chamberlain sent off - was a day they would certainly "never forget" on his 1,000th match in charge.
He said: "It was of course a very bad memory, but football is not made of history, it is made of performance and performance in the next game that counts, that is what we want to do."
Wenger has yet to get the better of Chelsea manager Jose Mourinho in their 11 meetings and on the eve of last season's encounter was branded a "specialist in failure" by the Portuguese coach.
The 64-year-old, whose side went on to lift the 2014 FA Cup at Wembley, is not about to get involved in any pre-match mind games.
"One of the privileges of age is that your ego is less important and you more offer your knowledge to what is important, and that is the performance of the team," he said.
"It is not a game between two managers, it is a game between two teams and two clubs.
"The recent history (at Chelsea) was negative for us and on Sunday we have a good opportunity to change history."
Wenger, meanwhile, maintained forward Lukas Podolski was still part of his plans, despite the German World Cup winner hinting he may look to leave to find more regular football.
Source : PA
Source: PA