he will probably have similair situation as isco had,i can see him being starter in season or two
Except that he doesn't have an ounce of Isco's talent.
If Zidane is still here by then, Casemiro will have his spot locked down (not that Ceballos could play DM anyhow), meaning it'd be in place of Modric or Kroos. Modric is the only real bet due to age, but replacing him with someone like Ceballos? Good luck on that
And even then there are players like Kovacic and Isco who'd be head of him in the pecking order - hell even Asensio could probably slot in there somehow ahead of him. Nah, Los Merengues will most likely buy a big name to replace Modric when the time comes, and Ceballos will be off on loan at Getafe...
Perhaps I'll be proved completely wrong in due time, but I honestly doubt it.