Arsene Wenger will need no reminding that his record against Chelsea leaves a lot to be desired.
Arsenal have won just five of their last 29 encounters against the Blues and, in recent years, Wenger's men have seemed to go to pieces whenever they have faced their rivals.
What will concern Le Professeur even more is that in the two most recent clashes between the two sides, the Gunners have had three players sent off.
SIGN UP NOW
Want to become a GMS writer? Sign up now and submit a 250-word test article: http://gms.to/haveyoursay4
While London derbies are always going to be a fiery encounter, there's no doubt that Arsenal need to be more disciplined if they're going to get the better of Antonio Conte's side this weekend.
The trouble with discipline, however, is that Chelsea have one major spanner to throw in the works - Diego Costa.
Costa isn't exactly the Premier League's most popular striker at the best of times, but at the Emirates, he's become a hate figure, and with good reason.
Last season, his antics changed the game, with Gabriel sent off for confronting the Spain international after he appeared to deliberately push Laurent Koscielny in the face.
Yet, while Arsenal had every right to feel a little hard done by, Wenger insists he has a plan to deal with Chelsea's controversial star this time around.
So, how do you solve a problem like Diego Costa?
"By being completely cold-blooded and just focusing on your game and not responding," Wenger explains, per the Daily Mail.
"Just try to annihilate his qualities and his game. You need to be committed but by respecting the rules of the game and not responding."
Discipline and focus
Of course, that could be easier said than done. Two seasons ago, even the more experienced Per Mertesacker was dismissed for an incident involving Costa.
It's not just his fiery temper that Arsenal will have to look out for either, as the Stamford Bridge hitman has already scored five Premier League goals this season.
Wenger will need to be cautious not to place too much focus on one player, but if his players lose their heads again because of Costa's meddling, it could well affect the result.
"For the result tomorrow, it will be important the way we play football and the way we behave," the Arsenal boss added.
"Discipline and results are linked."
Can Arsenal cope with Chelsea's attacking threat? Does Costa's ability balance out his ill-discipline? Have your say in the comments.