Dembélé has a history of recurring injuries → this could frustrate him. Enrique can help by maintaining the player's confidence, giving him space to slowly reintegrate into the squad after recovering. Enrique should have other options available. For example, PSG still has wing options such as Barcola, Asensio, Gonçalo Ramos (who can shift positions), or even a more offensive wingback scheme. They could also change their own game tempo, such as building up faster from the midfield, making more crosses from the fullbacks, or creating a false winger, and using a creative midfielder on the wing to keep the attack alive.
We all thought he is over all those injuries, it is really frustrating and I hope he doesn't think too much about it. I hope after he recovers it doesn't start reoccurring again like it used to he just have to let his body recover fully and not try to force things and also just as you said the coach needs to help him manage the injury and his fitness so he doesn't go back to being frequently injured. Just like Enzo Maresca did with Reece James in Chelsea. James used to have reoccurring injuries just like him but Maresca managed home well and didn't over work him that he has been fit for a long time now so if Enrique can manage him properly the injury shouldn't be a problem.