By Matt Fortune
An away win at Stamford Bridge on Sunday would not only be the first in four years but would also likely bring the curtain down on Chelsea's title challenge.
Three points for Arsenal would see them move five clear of the Blues, and should Manchester United emerge victorious from the first leg of Grand Slam Sunday, Chelsea will be eight adrift with seven to play. However their record is a proud one and it has rarely looked under threat - Avram Grant's side smashed six passed Derby in their last home fixture.
Of course, the Gunners have already inflicted defeat on Chelsea this season. William Gallas' goal in December put Arsenal six points clear of the west Londoners - a similar result this week could have even more significant repercussions.
We asked Tim Harrison on the Kensington and Chelsea News for his take on Chelsea's most recent London derby, dealing with set-backs, question marks over tactics and how one former Gunner could be fresh and ready to hit top gear.
"The game against Tottenham was absolutely extraordinary. In terms of the outcome it was pretty disastrous for Chelsea's season. The general consensus after the game that it was probably it in terms of the title for Chelsea. They needed to win every single game from here on in to have any chance at the title and it is a set back with two vital points dropped certainly. Arsenal and Manchester United still to visit so it is still technically there but that final equaliser by Robbie Keane, a beautiful shot that you had to admire, was a set-back."
"Anelka wasn't even on the bench in either of the last two games. The big question mark over him is can he and Drogba find the balance to perform together in the team? I suspect Anelka may start against Arsenal because of the slight rotation policy Grant uses. The big though hope, for Chelsea fans, is that Petr Cech will be back and there is a slight chance that he will be. Carlo Cudicini was certainly at fault with his positioning in two of the Spurs of goals.
"There was also Ivanovic and Di Santo signed in the January but we have not been able to see either of them yet."
CAUSE FOR OPTIMISM
"Chelsea are proud of their home record and they love it, but all records do have to end at some point and you have to say that Arsenal are capable of breaking it. But, and Arsène Wenger will have noticed this and will tell his players, after Chelsea have suffered any set-back in the last few weeks they have bounced back incredibly strongly. Look at the 6-1 win over Derby and the 4-0 over West Ham, they both came after the disappointment of the Carling Cup and Barnsley.
"Also I have to say, at White Hart Lane the passing seemed to be back to form, a lot of neat one-touch passing."
CAUSE FOR CONCERN
"The attractive football comes and goes. There is a niggling question mark over Grant's tactics under pressure and his ability to shut up shop. He put on defenders at odd times and took of key players - there was some disbelief that he had taken Joe Cole off. The defence of set-pieces let them down at Tottenham and oddly that has what has been the foundation of someone of their successes."
"I think there were questions raised over the tactics late on. Chelsea ended up with a five man defence which was rather perplexing, something I have not encountered in the last year or two. Alex ended up somehow sandwiched in the middle of the four. It ended up with people not being entirely sure of who they should be marking. Everyone was unfamiliar with the situation of trying to pack the defence and it ultimately backfired. Some of the defending at the end from set pieces was woeful."