Casemiro is said to be a target by PSG and Al-Hilal now. You know he has been quite far away from his old performances recently. This is why Manchester United are said to be thinking of parting ways with him. His time with injury didn't end up well for him. He is still a quality player but he needs to improve his effort much more than this.
This is part of the reason I keep saying PSG is not a very well-run club. PSG should have no reason to be interested in Casemiro. He is no longer what he used to be. PSG should be looking to sign better DMs like Zubimendi and Rodri. See how Casemiro is performing now in Man United, he is not at his best and I doubt he will ever get to that best again.
If I were Casemiro, I'd go to Al Hilal. He would play very well there because they have some very good players too that will complement him, plus the added advantage of being paid well.
Manchester United need new signings. They need a good DM because to me both Amrabat and Casemiro can't get the job done. Aside from the DM, they need good CMs that can hold the ball and distribute the ball very well. If they don't make good signings they'll continue to suffer.