If Alex fails to get a work permit, which is very possible, as Juan is taking his starting spot in the Brazilian XI, perhaps Chelsea will be sick of waiting for him to become eligible for EPL? Or maybe they would want to loan him to Juve so that he improves further? He doesn't have much else to gain by playing in Holland anymore. By playing at Juve, he'll be on a team that is expected to be very competitive as well as diversifying his game.
I think he'd be a nice choice, IMO. Has the experience, and people have taken their eye off of him since he broke his leg. May not have a lot of quality years left in him, but he provides leadership at the back which we lost with Canna and Thuram leaving. Only problem is the Portuguese language disconnect for the most part, but that didn't exactly hurt Emo last season.