I think that Thiago Alcantara could leave Barcelona. Thats not saying he will but it is looking likely.
Apart from the fact that he has barely played in the last couple of seasons although he clearly has the talent to, the arrival of Neymar has seen a vast number of fans buying number 11 Neymar kits... Really insensitive from the fans as it just so happens that Thiago wears the 11 shirt.
If you look at players like Gotze and Isco, playing every week is instrumental in their early development and Thiago is not getting that. So there is a 50-50 chance of him leaving - he may decide that he will get the chance at Barca this year.
Anyhow, aside from his astonishing technical qualities he is a tough player and there is no doubt he would flourish at City. I've watched him play for a while now and it would be a complete nightmare if united buy him.
If we get Isco - looking more likely with Pellegrini revealing a verbal agreement - I see no reason not to go for Thiago too because as optimistic as it seems we could be securing an Iniesta - Xavi like partnership for the future which would be awesome.