Chelsea manager Jose Mourinho congratulated Arsene Wenger on his 18 years as Arsenal manager on Friday and said he had no need to apologise for calling him a 'specialist in failure' last season.
Mourinho, in an unusually conciliatory mood towards his old adversary, also played down the significance of Chelsea's 6-0 win over Arsenal at Stamford Bridge in March and said that he did not think any side could match Arsenal's "Invincibles" of 2003-04 who went through the Premier League season undefeated.
Neither team has lost in the league so far this season either, with Chelsea topping the table after winning five and drawing one of their opening six matches, while Arsenal are fourth with two wins and four draws.
Mourinho told reporters at the club's training ground west of London he was looking forward to the match and for once praised Wenger and his 18 years at the north London club which he celebrated on Wednesday with a 4-1 victory over Galatasaray in the Champions League.
"It is an amazing achievement, congratulations to him and the club because it is not just to do with the manager's quality but also the philosophy of the club, so obviously I congratulate both, Arsenal and Mr Wenger."
He said Chelsea's big win over Arsenal in March would have no significance on Sunday, nor would the fact that he has never been on the losing side against Wenger.
"A result like that happens once every 50 years, not every year. It was not normal because Chelsea and Arsenal matches are usually close, so it was a bad day for Arsenal and an unbelievable day for us.
"But me against Arsene Wenger? I never had the pleasure of playing against him one against one, I've never played him at beach soccer, its always between Chelsea and Arsenal and Sunday's game is out of context to the past. What happened in the past, happened in the past."
There is plenty of baggage from the past between the two with Mourinho famously calling Wenger a specialist in failure last February.
Mourinho said when he made that comment it was in response to an earlier remark from Wenger saying that the league was "Chelsea's to lose" and that Mourinho "feared failure".
Eventually Chelsea did lose out with Manchester City finishing as champions, but on Friday the Portuguese said he had no need to apologise and the two men had moved on.
"I don't apologise, he didn't apologise. My feeling is not to go over it -- forget it, to move forwards without thinking about what happened. He doesn't need to apologise, so I don't need an apology or to apologise.
"Intelligent football people don't need that, it's finished. Lets go for another match with big responsibilities for both of us."
He also said he expected Chelsea to win on Sunday but did not think it would be possible for Chelsea to match Arsenal's unbeaten league season of just over a decade ago.
"Again, that is something that happens once in a lifetime.
"I don't see in modern football, with the competitiveness of this Premier League, that one team can be champion without a defeat."
The only other team to go through a league season unbeaten was Preston North End in the Football League's first season in 1888-89. "In my opinion (what Arsenal did) will stay in history as the second and last time it ever happened," he said.
