Chiellini is still playing for the U21 team but he has earned a respectable amount of caps (six) for a young player. I think he might be one of Italy’s next superstars because he is a good defender who can add to the attack and score beautiful goals just like he did against the U21 Spain. I also think Aquilani or Montolivo will be key players in the future.
Italy should just have a friendly with a random country anyway just to try out and debut thier young stars. A mix of key veterans like Zambrotta, Buffon, etc. can make these youngsters even better when they train and play together.