Yes, from an objective point of view. Show us your eleven.
I'd definitely let Grygera and Grosso go. I'd bring in someone like Rafinha for rightback, i'd try and bring in one of Tremoulinas or if he's not possible then i'd settle for Criscito. Fullback positions would be the most important transfer targets. I'd try to bring in a centerback, if possible Kjaer would be good.
I'd also let Poulsen go, as Juve has too many defensive minded midfielders, Poulsen is on a high wage and he isn't expected to play a lot of matches. I think a 4-2-3-1 system is the best possible system for this Juve team, but of course i would look into bringing a winger in. Someone like Krasic would be brilliant.
My team would look like this in the end
------------------Buffon------
----Rafinha-----Kjaer--Chiellini---Criscito
----------------Melo------Marchisio
------Krasic--------Diego------Giovinco

stuckup
-------------------Amauri