Won't: Lack of knock-out experience
There is no doubting the class of the Manchester City squad but the club has never before qualified for the Champions League knock-out stages and that will play against them.
Some kind of learning curve seems to be necessary in order to win what is arguably the strongest competition in football and playing twice in the group stages is not enough.
Granted, some of City's players have the experience from their former clubs but it takes time to build a winning mentality at a club. The fact that individual players have the experience is not necessarily enough.