Özil. But from your list I'd go for Silva. As much as I love Xavi, he's playing too deep these years to be a man of that last pass that is an assist. Nani will be overwhelmed by Young this season, and with Valencia back he won't nearly get as much playtime as last season I think
You have money for Nani, Özil AND Silva? I'm happy to help, but my advice is not to get Nani and get a top defender and striker instead. Your star players have to do awesome, and I doubt you'll have money left for decent top players with that crazy midfield
Sorry jeroen its young not nani. I already have young and benzima, now going to buy ozil and david silva. .... .... .... .... Buffon.... .... .... .... ....
.... Fábio Coentrão.... .... T. Taiwo.... W. Samuel.... .... F. Rodríguez.
I planed to go with 5 decent midfielders because these guys will do assist, score goals and also get points for clean sheets, whereas strikers get points only for goals and assists. And my subs are lamela, A. Chihi, K. Boulahrouz. So I have back up for defence, midfield and striker.