Arsenal manager Arsene Wenger has warned Manchester City they cannot afford to lose Saturday's showdown at the Etihad Stadium as his side look to increase the pressure in the Barclays Premier League title race.
The Gunners can steal a march on their rivals with victory in the match switched to a lunchtime kick-off for television, when Wenger's men can open up an eight-point lead, while City would be left some nine off the summit.
Wenger accepts the final outcome could have a big impact on the aspirations of both sides heading into the hectic festive schedule, which sees Arsenal host Chelsea on December 23.
"Of course [a win] strengthens your beliefs, but I am convinced we believe in ourselves anyway, no matter what happens," said Wenger, whose side were given little recovery time from the midweek Champions League clash away to Napoli, which they lost 2-0 on Wednesday night.
"But if you are in City's position and they lose, then they are nine points behind, so they have more negative pressure than we have.
"We have a positive pressure that we can make a big difference with them, so let's look at it like them.
"We have an opportunity to make the difference with everybody else tomorrow morning, early we play first.
"We have an opportunity to go from five (points) to eight, that is fantastic - we have to look at it like that."
Wenger added: "There is always a pressure as you want to do well and be the best, but it is positive (to be leading the table).
"We have a cushion, so we are not really under massive pressure.
"We have an opportunity to show our strength and that is what we want to take."
Wenger expects a much-improved display from their last visit to Manchester, when a slow start resulted in a 1-0 loss at United in November.
"That is what we can learn from Old Trafford, is that it took us one half to be completely ourselves," the Arsenal manager said.
"I think we have learned from that and we will go into the game tomorrow on full cylinders.
"I believe first of all that you need a strong defensive performance and maybe the best way to do that is to attack and [keep] the ball and not let them find their flow."
Wenger has challenged his side not to lose focus following a 2-0 defeat to Napoli - which saw Arsenal qualify for the knockout stages as Group F runners-up - with the domestic fixtures coming thick and fast over the next fortnight.
"I don't deny that every game has a vital importance because of the influence on confidence, or the belief of the team," the Gunners boss said.
"I believe what we just want from our team is to show during this period that a huge level of commitment and belief, that can make a massive difference but the period is important."
England forward Theo Walcott could be in contention to start against City, while full-back Bacary Sagna may also be fit following his hamstring problem.
City midfielder James Milner admits he does not know the secret behind the team's free-scoring home form - but hopes it continues against Arsenal as Manuel Pellegrini's team to maintain their 100 per cent record at the Etihad Stadium.
Pellegrini's men have won all seven of their home league games this term, notching an impressive 29 goals in the process.
This has contrasted with an away league record which features four defeats and Milner is at a loss to explain the difference.
He said: "Who knows? We have been playing pretty well away as well for most of the games, but we just haven't had the luck or we haven't finished our chances as well as maybe we have at home.
"But we are on form at home and we are scoring a lot of goals, so it is important we continue to do that."
But City will certainly take some encouragement from their most recent away performance - their stunning midweek fightback against European premiers Bayern Munich in the Champions League.
The gloss may have been taken off City's 3-2 win at the Allianz Arena by confusion over their understanding of the goal difference rules - they had to settle for second place in the group when another goal would have secured top spot - but it was still a notable result in the club's development.
It also came after Pellegrini made seven changes and Milner believes the form of the whole squad must be a good thing heading into the weekend.
Victory over Arsenal would lift City within three points of the top spot.
The England international, who scored City's winner in Germany, said: "I think with the quality we have in the squad, there is always going to be competition for places.
"When you train every day you have to perform and when you get a chance on a Saturday or in the Champions League, you just want to get out there and play well.
"I think it's healthy for the team that you have to play well to stay in it."
City are still without central defender Matija Nastasic (calf) and right-back Micah Richards (hamstring) is doubtful after being forced off against Bayern but left-back Gael Clichy has overcome a knock.
Playmaker David Silva made a successful return to action in Germany after a six-game absence and striker Stevan Jovetic (calf) is also back in training.