Arsenal had reluctantly sold the Spain midfielder back to his boyhood club for £30million in June 2011, and were understood to have first option should the player come back onto the market.

A potential deal, though, never materialised as Fabregas – who played more than 300 games for Arsenal since breaking into the first-team as a 16-year-old - instead opted to join up with Jose Mourinho at Stamford Bridge.

When the matter was raised earlier this season, Wenger insisted he had not spoken to Fabregas directly about the possibility of a transfer, with Arsenal already set on recruiting Chile forward Alexis Sanchez and with plenty of other options in the Spaniard’s preferred position, The Frenchman said he felt the “deal was done a long time ago, early 2014”.

The Arsenal manager refused to be drawn further on the saga when pressed at Thursday’s pre-match media conference ahead of this weekend’s showdown with Chelsea at the Emirates Stadium, but indicated all was perhaps not as cut and dry as it appeared from the outside.

“We will have to discuss that one day, with all the terms... it is not as clean as that,” said Wenger when asked why he chose not to bring Fabregas back to the club, when it was his decision rather than the player’s.

“I cannot speak to you about that (reasons) now because that will not help us to win the game on Sunday.”

Put to Wenger that it was then Fabregas who chose not to come back, the Arsenal boss replied: “I don’t know, I don’t know.”

Wenger accepts even if his side win on Sunday, then it would remain a bit ask to overhaul the leaders’ advantaged in the closing six matches.

“Mathematically it will be possible, but Chelsea have their future and the championship in their hands,” said Wenger, who rates centre-back Per Mertesacker as only “50/50” to be fit on Sunday.

“What we can do is get closer to them and we have an opportunity to that at home. We want to take it.”

Do reduce the deficit, Wenger must get the better of Mourinho for the first time in 13 attempts.

Arsenal were thumped 6-0 at Stamford Bridge on Wenger’s 1,000th match in charge last season, and the pair had to be separated when they went toe-to-toe in the touchline when Chelsea ran out 2-0 winners in the Barclays Premier League in October.

The Arsenal manager was branded a “specialist in failure” by Mourinho, but played down suggestions it was all about the men in the dugout.

“It is not a confrontation (between managers), it is a confrontation of two teams,” he said.

“Football is down to the fact that the performance on the day will decide the game and the result, so let’s focus on that.”