Both are desperate to keep up with the title pace, with Arsenal boss Arsene Wenger describing the clash as a 'must-win game', while Chelsea counterpart Carlo Ancelotti has declared: "We don't want that gap (to United) to widen, so it's important to obtain an important result in this game."
History is on Chelsea's side, with the Blues having won the last five clashes between the pair, the latest a 2-0 triumph at Stamford Bridge in October.
The Blues have also won on their last three trips to the Emirates, where Arsenal have been less than convincing already this term, being beaten by Premier League newcomers West Brom and Newcastle, as well as arch rivals Spurs.
But, in the Gunners' defence, Wenger's side go into this clash in better league form, taking 12 points from their last seven top flight games - including four wins - while the Blues have only mustered six points, with just one victory, to see them drop from top to fourth.
However, Chelsea will by buoyed by an improved performance in the 1-1 draw at Spurs last time, while the second placed Gunners are seeking to bounce back from a 1-0 defeat at Old Trafford.
Chelsea striker Didier Drogba, who scored but also missed a last-gasp penalty in the draw at White Hart Lane, will be looking to continue an amazing run against the Gunners of 13 strikes in 13 games, including five goals in the last three meetings.