Don't forget that last season's semi-finalists Inter just had to be willing to be positioned below Sociedad in the group phase so they need to be wary even though they are dark horses.
The current situation for PSG remains a favorite in the match in the round of 16 this time but that does not mean they will win easily in this match considering as I said Sociedad is a dark horse that could surprise.
If in the end PSG let their guard down or underestimated Sociedad, they could lose the match later. The advantage that PSG has is that at least some of their players have known how Sociedad plays because surely Asensio and Dembele know what to do because this is not the first time for them to face Sociedad.
Paris Saint Germaine will not only make rely on their best players to destroy Real Sociedad but will also be doing their best by playing more like a team in other to eliminate Real Sociedad because if they choose to rely on individual performance of their star players, their opponents Real Sociedad might just capitalize on that and win the tie.
Currently, when facing PSG, they will not be a favorite club and I am quite sure for the first leg Sociedad will only aim for a draw by implementing a defensive scheme and continuing with a counter attack.
The problem Sociedad have to think about now is how they can close Mbappe's movement for PSG because as long as Mbappe is closed, PSG will not be free and this could be a good advantage for them.
PSG is a pretty good club and their attack is still very good today but indeed when they are closed with a tight opponent's defense they will try harder and override the defense so that is what Sociedad should look for in their match in the round of 16 this time.