Between us and Bayern if it were to happen but how could Barca replace him? Didn't he sign an 8 year deal not too long ago? I can't see them parting willingly for any amount of cash.
Besides, if we aren't prepared to pay a small agent fee for Isco, would we be prepared to pay a massive one for Messi? I'm sure his agent or any slimeball in with a shout would be all over it.