There are 2 definite outcomes in this match and my prediction is PSG wins or Rennes manages to draw. But it would be more comfortable to bet on BTTS (Yes)
PSG should rotate players and save their main players. Because as you said in the next few days PSG must appear in the UCL. It is impossible to sacrifice the physicality of the main players which can affect their performance in the UCL later. So I believe in today's match both teams to score.
BTW, do you also predict the result of the Marseille vs Lens match? It seems that in this match Marseille will avenge their defeat in the previous meeting and currently Lens is having big problems with several injured players. Do you believe that Marseille can win the match against Lens?
PSG did the thing I expected and rotated the usual starting lineup. However this still didn't change anything and they won by 4-1.

Dembele even scored 2 goals in the stoppage time after entering the game late.
Luis Enrique must be really happy now. However his task at Anfield is going to be so difficult... Nearly mission impossible.
About the
Marseille - Lens one, I would prefer
Marseille win @1.46. Lens are hopeless with 4 losses in 4 weeks recently.
Dembele is a very different player. It was amazing that he came on later and scored two goals, it made his goals today more memorable, everyone is talking about Dembele. I think this change in Dembele is due to the coach, I remember his form in Barcelona, it has nothing to do with the game he plays now, Luis Enrique does a great job on his players.
PSG thus continues to collect the three points, it was a great win against Rennes today.