1) He has leadership qualities
Does he? To me, a leader, in addition to usually being one of the club's top players, is one who
lifts the rest of the team when they're down. Who shows up, consistently, on not just big occasions, but against lesser opposition as well. He's the guy the rest of the team looks to as an example in-game. I don't think Marchisio embodies this at all. He is criminally inconsistently, struggling to be relevant on the pitch more often than not. On top of that, his good games almost always run concurrent with great
team performances. This suggests to me that he's more of the "supporting cast" type and not the man who can set himself apart as a captain should be able.
Seriously though, giving this guy the captaincy
if he has a good season? Just one? Just like that? No chance. He should put in a good month before we even get onto talk of a good season.
Besides which, Buffon and Chiellini both are much better candidates.