The new Champions League format leaves plenty of margin for error for clubs aiming to reach the knockout rounds, yet European heavyweights such as Real Madrid and Paris Saint-Germain are currently at risk of an early exit.

Europe's flagship competition has been revolutionized to breathe new life into a tournament that had not undergone any changes for two decades.

The alterations, however, were also made to satisfy the continent's biggest clubs by providing more games — and more revenue — at a time when the threat of a breakaway Super League hung in the air.