"It is even beyond the dreams that you have as a child. The Azzurri shirt is special because you represent your national team. The tension of international matches is not reached even in the most important club matches," he told Sky Sports.

"At this age, I cannot make long-term plans. I live with the enthusiasm of a novice, call-up after call-up.

"After Italy-Sweden I made a long reflection, and I came to the conclusion the national team is something you cannot refuse. As long as the coach calls you, you have a moral obligation to respond."

Chiellini was not part of the Italy squad who won the 2006 World Cup and has suffered heartbreak when were knocked out in the group stages in 2010 and 2014 and failed to qualify for the summer tournament in Russia.

He said: "It's a regret that I will always keep behind, for the two eliminations in the group stage. The lack of qualification to Russia? Within us, there is so much disappointment, certainly, because it is an emptiness that we carry inside."

Italy are two points behind Portugal because, as well as winning, they also need Portugal to lose in their final game against already relegated Poland on Tuesday to make it to the finals.

Cristiano Ronaldo has been left out again by Portugal boss Fernando Santos, who omitted the 33-year-old, saying it was by mutual consent, for last month's internationals as he was still adapting following his move from Real Madrid to Juventus.

Andre Gomes has been sent home with a bruised leg while Italy are without Federico Bernardeschi (adductor) and Leonardo Pavoletti (muscle problem).

Portugal beat Italy 1-0 but Napoli defender Mario Rui expects a different proposition on Saturday.

He told the Portuguese FA: "We are going to face a team that has changed a lot since the last meeting. Italy will play differently, it has great quality, but it will face a Selecao with the same objective.

"We want to continue what we have done, that is, to play well and win the game and take on the first place. We are more than prepared for this game."

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