It just doesn't get any bigger than this in the Champions League group stages.
It's the champions of England hosting the champions of Spain. Both teams are coming off of domestic victories that saw them score five goals apiece and will see this match as a must-win.
If Madrid fail to get at least a point, they would be in position to finish behind Borussia Dortmund in Group D—which would see them playing one of Europe's best teams in the knockout rounds.
If City fail to win all three points, their Champions League run would be over without reaching the Round of 16 for the second straight year.
Both teams are in good form and have enough talent to beat any team in football on their day. The question is, which one will be in better form in Manchester?
As we prepare for the clash, here are six players who will play a key role in their team's aim for victory.