I am actually excited about this match. If we do eliminate Lyon, I agree with Sarri that everything is possible from there on.
In order to win a league, you need to have the best team. I'd say that 90-95% in winning a league is about having the best team. Only if 2 or 3 teams of similar quality fight for the league, some other factors can decide who wins it.
In order to win the CL in normal season, 60 to 70% is about having the best team, while factors like current form, injuries, lack of concentration in crucial moments, or even a referee mistake or two might screw you up. Still, in normal seasons, quality is absolutely the main factor. Teams have enough time to prepare for matches, for observing the next opponent and prepare for them, and, after all, the best teams are set up to peak in March-May.
This time it's completely different to any other time in history. At most 40-50% will be about quality and playing the best football. This means that teams like Bayern or City are still the favorites, but with 4-5 days between matches, without time to prepare for the next opponent, with only one match deciding who qualifies and who doesn't, with hot weather in mid-August and humidity above 60%, without any chance of predicting the form of teams who finished the official season almost 2 months ago in Germany or 5 months in the case of France, or the teams who played every 3 days until yesterday. No crowd. Even a minor injury of important player (which would normally keep him out for a week) can now be a catastrophe.
If we pass Lyon, everything from 5:0 defeat in the quarters to a CL win is just as possible. We'll have a 1/8 chance to win it, just as everyone else. We didn't click as a team, and in a normal season our chances to win this year were very small, or at least much smaller than 1 in 8. But in a season like this.... who knows. And that's why I am excited about the Lyon match.