Real Madrid got an unsatisfactory result in La Liga, before undergoing a Champions League match against PSG. I think Paris Saint-Germain should be able to see where Real Madrid's weaknesses are if we look at some of the matches yesterday. Yes Real Madrid's front line is a little unproductive, they are only able to score 2 goals from their last 3 matches. This is really a weakness that PSG should take advantage of.
PSG's play will be radically different from the style of play of Villarreal and Mallorca. I don't think that PSG will sit on the defensive and look for luck in counterattacks. PSG will most likely try to dominate the entire match by offering Real Madrid a game at high speeds. And in such a game, everything will depend on the physical condition of the team.