Just imagine the bash Marchisio would get if it was Juventus and him instead of Chile and Vidal.
Sorry, but I don't see the point of replacing Marchisio at this point when what we need is a DM to play alongside Pirlo and not a useless move that would waste a non-eu spot. If he's coming for Melo's place, then it's even more stupid, because they're different players.
You don't like Marchisio? He had a bad season? Fine, let him leave underrated after a season with Del Neri. That's definetily a wise move!