Ogbonna has already starred for the Under-21 side, but was added to Cesare Prandelli's squad when Alberto Aquilani pulled out injured.
"I was surprised by this call and I absolutely did not expect it," confessed Ogbonna.
"I am very happy and excited, as it's like living a dream. Giorgio Chiellini was the first to compliment me on getting here, as we play in the same city.
"I have known him and Andrea Ranocchia from our Under-21 days, so they helped me to settle in."