There's not a big history of players leaving us and going on to much better things so don't think that statement has much validity Mikey. Rooney obviously, but that was a certainty and we were well reimbursed at the time. Steve McMahon possibly too. Can't remember anyone else having a distinguished career elsewhere after being sold.
Isn't the clause 12m euros anyway?, so it's only about £10m, not £12m. Personally I can't see Barca exercising the clause as I don't think he fit's in their system. I don't see them utilising him in their squad for a season so I doubt there's enough profit for them to pay him for 12 months before selling him on.
Milan appear to like him so I thin there's more chance of them taking him. Or he may come back here which I wouldn't mind to be honest. If he get's himself fit he'll find it a lot easier under Koeman.