In that competition, Europe's finest anyway. Not sure I buy the "weaker" theory. Entering funky territory if we say this or that year the level was higher in a competition (Liga, World Cup, UEFA, CL, CA etc) than this or that year. For example ManU. Their absence imo didn't make the round of 16 weaker, as there was a team who beat them in the group stage (Basel). Now, as a participant in the round of 16, is Basel tougher than ManU? Maybe not, but when Basel beat them, is it right to say the weaker team made it through while the better ManU did not? No. Not saying it's this simple exactly, but: CL is a tourney that decides European club championship. In Group stage, best 32 clubs of Europe. From then on, every round cuts 50% of clubs away. The level in any stage of the competition any year? "The best Euro clubs can offer".