He can go.
Tell you what I'd say to him:
"Hi Carlos, you hand it in, and you're banished from property used by the club, you're also fined your wages every week, and you're not moving to an English club, and if you move to Real we'll only sell you if we get Higuain and Ronaldo, if it's Barca we want Messi and Villa, otherwise you can rot."
Sick of his attitude, why can't the Sheikh just get a henchman to put a bullet through Kia's head? would solve everything.
Carlos, you're a fool, and you'll be shown up to be. We're bigger than you, better than you and will carry on regardless and still win like we did today.
You, on the other hand will warm a bench somewhere.
Good luck. Now either grow up and be grateful for what you've got and fuck Kia off, or fuck off. Plain and simple.