We know that one of the aims of the club was to ensure that there were two players contesting each position within the squad. The additions this past summer was evidence of this: Willy Caballero, Bacary Sagna, Fernando, Eliaquim Mangala; all players who not only provided depth but could be called upon at any point.
We have seen this proven in recent weeks as Manuel Pellegrini has seen his side hit by injury and suspension to key players for key games, the epitome of this in Rome this week when he was selecting sans Sergio Aguero, Yaya Toure, David Silva, Vincent Kompany and Aleksandar Kolarov.
Much has been made of the comparison between City and Chelsea's squads this season with it being considered that they look to be very equal in terms of depth and quality.
Jose Mourinho talked plenty last season of City's squad, how they were the 'ideal age' and you can see with the additions Chelsea themselves made in the summer that he felt this was an area they were lagging behind City on.
Mourinho spoke of the depth of City's squad again this week in the lead up to the weekend:
"They have a magnificent squad, full of top players, of end products.
"These are not young people to develop. If he doesn't play one player, he plays another one. He went to Roma to play a Champions League match without two or three important players, and they won. Just because one player is missing, they don't have a problem."
One thing Chelsea haven't had to contend with this season is injury. In fact, Chelsea suffer very little from injury and this had led to them having a great deal of consistency in terms of selection. They now though face a period of 19 days to the end of December where they have six games to contend with (City do not have a Capital One Cup game) and Mourinho has said there will have to be rotation - "I don't think a single player will play all six matches" - something he has not always been keen to do (trust issues with some of his squad?).
City have proven their depth over the past month or so and yet remain just three points behind Chelsea. Even if they avoid a number of injuries you think at some point Mourinho has to think longer term. Chelsea clearly have some key players who can match who City put out, but does City have the advantage of strength in depth? And will this affect the title race?