The Brazilian-born ace insists he "feels Italian".
Motta said: "I hope to play a great game. It will be a special evening. The emotion will not be comparable with anything else I have been through in my career so far.
"I feel privileged to have this opportunity and I will try and take it to the best of my abilities. The national team shirt was the one of my dreams. I have the chance to make it come true after many years and I am happy for this.
"I was born in Brazil, but I feel absolutely Italian. I am very happy to be here with my teammates.
"My family comes from Italy. I didn't have the luck to be born here, but I feel completely Italian. I know the national anthem, but I won't sing it only because I don't know the melody.
"I don't know what they think in Brazil about this decision. I don't believe that they consider me a traitor."