Since visiting the Britannia in late September and failing to win the match, it has been rather tough for the Champions, who prior to that encounter were playing some of their best football.
Now a few months down the line, they're trailing their biggest rivals by five points, but it's the performances that's worrying for fans.
Many would know, United might not always play the prettiest football, but results are what matters most.
With those words in mind, the argument that "A wounded United, strongest in the league" can be justified, tough encounters whether it be against one of the so-called big six, or against the lower half of the table, roughing out 1-0 victories has sometimes been part of the struggle that has won Sir Alex so many crowns.
City might be steering the wagon, and doing it in fine fashion, but can they sustain that excellent form, can they get up and start again should they fall and most importantly can they manage to keep their heads above water in the tough away games when all seems gloomy?
On the other hand, if United continue winning whilst in poor form, they could kick on and take advantage should Manchester City slip up.
The next couple of weeks are in actual fact the most important for both Manchester clubs. United have a decent run against slightly easier opposition whilst City face some tough matches in the league and Europe.
It could be the toughest test the current City side under Mancini will face this season. Bayern Munich will visit the Eithad Stadium followed by a scary visit to Napoli.
United could find their feet over the next couple of weeks with the hope they can gain some points on City. The biggest test in any league campaign is at the midpoint.
The league standing come the new year will in many ways determine which way the title is swinging.
While Mancini will be pleased and very comfortable with his current status, he could grow to be concerned should United start scoring. The pressure to stay at the top is much more than actually getting there.
Luckily for him and the City faithfuls, they now have a strong side that believes in themselves and in the structures of the club.
But having watched the league for so many years, it would be the biggest mistake to write off United just yet; wounded as they may be, they are still the strongest competitors to any challenger.
For those of you who will argue that "fact", it's merely based on history, history of the last twenty years, which prove the most successful club in England during that time will not give up so long as the candle burns.