That's highly debatable. First of all, Messi was lucky enough to be in a team like Barca where youth is promoted and encouraged. At Juve, people seem to think that a player isn't ready untill he's 25. It's tradition more than anything else.
I'm not saying he is better than Messi but he is in the same level if not better than Pato. If Pato is getting first team football then I don't see why Gio shouldn't. He isn't short of talent and he has monstrous playmaking abilities, exactly what this team need.
How can you be convinced he isn't ready to lead Juve when he hasn't even gotten the chance? I say we take a gamble and try him out. Let's play a diamond midfield which would give him the traquerista role, if he performs badly then at least we tried and will have no regrets. We can then move on.
If he succeeds, a new era at Juve might have just begun. The only difference between Giovinco and Messi, Fabregas, Pato, Aguero is not lack of talent, it is lack of faith from his coach, and even some fans.