Sunderland boss Steve Bruce admits none of his squad are off limits.
Bruce concedes every players has his price.
"I think it's wrong for any manager to say that a player is categorically not for sale," said the Black Cats boss.
"Do you think Manchester United wanted to sell Ronaldo? No. But when Real Madrid offer £80m, what do you do? In my experience, and I've been in management for 10 or 12 years now, what usually drives things is the player.
"Sometimes they have their head turned by money, sometimes it is the chance to succeed and win medals.
"I don't think there is anything wrong with that, because that desire to succeed is what drives the top people in any field - football, business or whatever.
"It's normal. It's what makes the world go around."
