I think the main problem, as has been pointed out several times on this thread, is that he doesn't want to come. Add to that his injury record and his apparent bad attitude at times too, it just spells disaster. A loan wouldn't be a bad deal, but if we had to pay his entire wage and he ended up injured for most of the season, that would be a bit of a waste in all fairness.
Also, if he's forced out of Barca and joins us reluctantly when in reality he wants to fight for his spot, then is he going to give it his all? Knowing his head would still be in Barca and he never wanted to come.... not too sure you know. It didn't work out too well with AdM