The Gunners have a one-point lead on United at the top of the table, so Monday night's meeting is one of the most important to date, as a four-point lead would raise confidence in the squad and perhaps help them on their way to gaining their first title since 2004.
However, the North London side may be without skipper Fabregas, who is suffering from the hamstring injury he picked up against Braga. Boss Arsene Wenger has admitted it is unlikely he will feature, but the Spaniard is determined he will make a contribution.
"If I can play in any way, I will," said the Spanish midfielder in The Sun.
"It's a huge game on Monday and we could go four points ahead at the top.
"We're definitely looking to go to Old Trafford and win. That would be a massive statement of intent for us. We are really going for it."
Although the Red Devils are still to lose a game in the league, they have dropped a surprising number of points, drawing seven from 15. Along with Arsenal, Chelsea have lost four games and Manchester City and Tottenham are showing signs of inconsistency and the 23-year-old has spoken of how tight the title race is and that his side cannot afford to keep on slipping up.
"Normally in December you see teams at the top of the table with 40 points or more. At the moment, we are sitting there with only 32. It is so weird.
"None of the top teams are at their best and that's making it very difficult for any one of them to break away.
"At Arsenal, we are clearly delighted to be top of the table, but we have still lost a few games already, particularly at home, which is very unusual. It's hard to explain. It's odd.
"And though Manchester United are unbeaten, they are not miles ahead because they have had so many draws - nearly half their games, I think. That's not like them.
"We are in a good position and we are very confident. We are winning games, playing well and scoring goals.
"We believe we are capable of beating anyone, anywhere.
"We still need to improve if we are to win the Premier League.
"We are winning games again now but know we can defend better and attack better. We know we can be more compact as a team.
"We also know it will be very tough, because I am sure Chelsea and United will both find their form and both will fight to the very end.
"So the more games we can win now, the better - and where better to start than at United?"
Unfortunately joining the injured Fabregas is defender Kieran Gibbs, who is out for the clash at Old Trafford, after picking up an ankle injury against Partizan Belgrade on Wednesday. Manchester United, however, have a clean bill of health after been boosted by the return of Rio Ferdinand - who picked up a hamstring injury against Valencia midweek - Paul Scholes (groin) and Patrice Evra.