Are you for real?
We signed him for £4mil last summer. He had a good season last season. Good, nor great and he wasn't even close to being the best centre back in the division. He was 6/10 at best in the majority of matches after a bright start.
This season he's been an absolute shambles of a player, responsible for more costly errors than any other player.
Who is going to buy him? A Premier League club? A newly promoted team who will have been watching him this season? A foreign team? Maybe a foreign team if we're lucky.
We'll be lucky if we get our £4mil back. £10mil or more? Get real.
If you are joking and being sarcastic then ignore the above.