PSG is a very good team, but of course defending the title is one of the things that can cause a lot of pressure, in this aspect PSG must act intelligently, Luis Enrique wants to do what he does again, repeat history, he wants PSG to be a very good team and win Ligue 1 and the UCL, they can do it, but it is not easy.
PSG are one hell of a good team in the world of football and they have proven that to us by winning the UCL not to mention the domestic titles. The manager might be facing a very tough task this season because all eyes are on him and his team so is like the other clubs are coming for PSG to dethrone them in all competitions. As the Champions they need to be ready so this time around the challenge won't be as it was last season, I'm saying this because PSG are now facing too much of injuries with some of their key players which is not healthy for them in any way, what more can Enrique do to make the squad depth be better? No Ousmane Dembélé and Désiré Doué, these guys will be missed in the squad, so is now or never for the other players to step up if not PSG might have some terrible games as in performance out there without these players especially when they have the Champions League to play but let's see how they go about business against Lens in the Ligue 1 today, can they be at their best in today's encounter?
It's normal for depending Champions to be pressured by the general football fans nor to talk of the Champions League defending Champions, Ofcourse all eyes would be on them to see if they'll replicate similar performance of the previous season although I don't expect they'll, maybe they could reach the Quatar finals or Semi's but lifting the trophy again, I doubt.
If it's in their domestic league competitions, I don't thnk they'll be missed but they'll definitely be missed in the Champions League, those players played a major role in PSG having their best Champions League season and it's quite unfortunate that they won't be available to do similar thing in the beginning of this season Champions League tournament but as for Lens, PSG would scale through.
It could be that they may not win the champions league again because is going to be hard to win the title and still go back to defend but they still have to try to get close to the semis or quarter finals like you said, you know they can't do it or get that far if they still have injury players who we all know are the reason or are the same guys that played a major role in them getting to where they are now as champions of Europe.
About the players I feel they can regroup and get back to join the squad, they will be out for 4 to 6 weeks respectively and I still see their replacement as players to cover for them till they get back. Enrique need to change his plans to the players to suit in if not they might be playing something different while the coach is instructing different as well but they are still going to make their opponents feel the pressure they are coming with just like they did with Lens in today's encounter.