Roberto Mancini's success at the club was built upon a strong defence, which he then built upon again to also make them an attacking force when they won the championship last season.
But so far this term they have failed to keep a clean sheet in any of their games and have generally looked disjointed.
The defeat at Real Madrid in the Champions League last week is the perfect case in point. Obviously, losing to the champions of Spain at the Bernabeu is no shame in itself, but to concede three goals in the final 15 minutes is just not what we have come to expect from this City side, particularly as they had led with five minutes remaining.
A lot of their problems stem from Mancini not seeming to know what his best team is. Every top club needs to have a big squad with strength in depth, but when it comes to the biggest matches the manager should know who the 11 men are he can turn to against the best opposition.
The fact they only did the majority of their transfer business at the last minute will not have helped. Suddenly Mancini has five new players he needs to integrate into the set-up with the season already well underway. Javi Garcia looks a good player, but for him to come in on the same day as Nigel de Jong left is going to have a disruptive effect. Even if the player himself settles in quickly, the rest of his team-mates each have to adapt to him, too.
Manchester United, Chelsea and Arsenal all made at least one significant signing early in the summer, and we have already seen how those new additions benefited from having a decent pre-season at their new clubs.
Another problem facing Mancini is the form of David Silva. During the first half of last season the Spaniard was in incredible form, head and shoulders above the rest, and looked like a serious candidate for the top individual awards. He finished the season with the most assists in the Premier League, but he never looked quite the same player in the second half of the season.
At times it is almost as though he is not certain of what his best position is. He is naturally a player who likes to drift around, but City should be looking to base the whole way they attack around him. Look at Shinji Kagawa, Santi Cazorla or Eden Hazard - a lot more seems to go through them than happens with Silva with City at the moment.
As a result, this season City seem to be unable to make the transition from defence to attack, and vice versa, as smoothly. Without that link, they are either throwing everything forward or concentrating solely on defence, which is why we have seen many of their games be so much more open this season than they were last term.
The loss of Sergio Aguero on the opening day was a blow, but there was more than enough talent in the striker department to cover for his loss. The problem lies in how the team is set up behind the forwards. How quickly that issue is resolved will have a direct effect on how quickly they can hit top form again.
It is always difficult for teams to retain a league title after winning it, but City are not helping themselves at the moment.