Manager Arsene Wenger insists a potential move for former Arsenal captain Cesc Fabregas to return to the club in the summer before he joined Chelsea was not as 'clean cut' as it might have seemed.
Fabregas, 27, has been integral to the Blues' Barclays Premier League title challenge this season after joining from Barcelona ahead of the 2014 World Cup.
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."
Whatever transpired behind the scenes last summer, it remains to be seen what sort of reaction the former crowd favourite will receive from home supporters on Sunday.
Wenger maintains it should not be hostile. He said: "I want every player to be respected, and Cesc Fabregas when he comes to the Emirates on Sunday to be respected like he deserves.
"The regret I have is that he wanted to leave here. This club and myself had a very positive influence on Cesc's life, so I would be a bit uncomfortable to have to justify today why he is not here.
"I believe I would rather it was the other way around."
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."
Wenger continued: "We have not always lost, first of all, in 12 attempts. We have come close to beating them a few times and they have always had very strong teams.
"We are on a good run and we have an opportunity to beat them at home, and we want to take it."
Chelsea locked down their 1-0 win against United last weekend to move 10 points clear, but Wenger feels it will be Arsenal's responsibility to deal with whatever tactics are deployed by the opposition at Emirates Stadium.
"We will adapt to what they do and try to find a solution. The challenge for us in top-level sport is to find solutions to every problem you meet," he said.