Zaniolo struck twice for Italy in their Euros qualifying victory over Armenia - making him the youngest Roma player to do so.
"Zaniolo has understood what it means to be an important player. His maturation is in process," said Capello.
"His ideal position is the same as Savicevic, on the right in attack, just like in the first half against Armenia. That's where his talent lies, with strength, speed and technique."