PSG is a team with a much superior quality of players in this tournament, and the League 1 trophy is almost for them every season.
Talking about Clermont, they only won 1 point after the first 6 rounds in Ligue 1 this season and are returning to the French Second Division. Compared to last season, Clermont declined so much that fans couldn't recognize their favorite team. If Mbappé does not start this match, PSG still has a high win rate. Goncalo Ramos or Bradley Barcola will replace him. They and Ousmane Dembele will create a new spearhead for PSG. PSG has begun to stabilize the squad. Even when playing at home, it will be difficult for Clermont to create a surprise against PSG this time.
I think Clermont is not going to be an issue for the Ligue 1 giants cause their currently at the bottom of the table and are yet to win any game, which shows that their performance this season is very poor and I don't think they'll be strong enough to face PSG who destroyed Marseille in their last match and have good quality players that are currently in form, even though Mbappe is in a good form I don't think the coach would want to start him he'll like to rest him against their champions league match against Newcastle.
Barcola's performance was very brilliant against Marseille and could likely be Mbappés replacement to face Cleremont foot, but theirs still other good options especially Kolo Muani who scored brace against Marseille, but I don't think the match against Clermont foot would be tough for them, Enrique might probably rest most of his key players, to be very fit to play against Newcastle.