I believe he is still under warranty, if you don't want it, we'll take it back, no questions asked.
If you're now happy with Varane, you will love Casemiro.
Most Madrid fans were happy when Varane left, I was amongst them, but Casemiro is still one of the best if not the best DM in the world, and will remain like that for at least 3 or 4 years, probably more, unless yor "break" him.
That reminds me a joke from Jimmy Carr, it goes something like this:
Jimmy Car is having sex with his girlfriend and he is unable to perform satisfactory.
His girlfriend tells him not to worry, that is normal and that it happens to a lot of guys.
To which Jimmy responds: "First, who are those a lot of guys" and "Second, if it has happend to more than one of us, could it be YOUR fault.
Something to think about...