Sassuolo attacker Volpato is set to make his Socceroos debut against Switzerland on Saturday (5am Sunday AEST) at Snapdragon Stadium in San Diego.
The 22-year-old stunned Australian football when he switched allegiances last week, after the Italy youth international previously wanted to wait for a senior call-up from the Azzurri.
Volpato hasn't spoken to media since, but in a video interview released by Football Australia on Friday indicated the turning point was the prospect of playing in this year's World Cup, which Italy didn't qualify for.
"Obviously, playing in a World Cup for your nation is something unreal," Volpato said.
"Playing for Italy also was good and amazing.
"But maybe when I was 18, maybe I was a bit too young, and maybe I was a bit too scared to make the change straight away, so maybe I was in my comfort zone a bit, playing for Italy.
"Something - I don't know - in my heart just said 'I think it's time to come home'."
As an 18-year-old at Roma, Volpato knocked back Graham Arnold's pitch to join Australia's 2022 World Cup squad, then this March said he was waiting for a call-up from Italy's senior team, before his change of heart.
"I'm Italian and I'm Australian, so it's actually been a big decision that's always been on my head 24/7 for quite a while," Volpato said.
"It's really hard, because it's like people want you to choose something, one or the other.
"But at the end of the day, a lot of Australians were brought up being both - being something else and Australian and obviously you don't want to choose one or the other.
"But it's been hard and, obviously, I do feel Australian, so it felt really good coming in, being brought in by the boys, and speaking English - Aussie."
Volpato spent a long time talking with Popovic - who made it clear he wouldnt "beg" him to declare for Australia - and close friend Alessandro Circati about his decision.
Sassuolo and Circati's Parma played on the last day of the Serie A season.
"He was trying to convince me, and I was like, alright, I'm gonna come, I'm gonna come," Volpato said.
On Friday, Popovic declared Volpato "fit and available" to face Switzerland and expected him to get minutes, after the attacker arrived in camp too late to play Mexico.
Popovic said Volpato was looking his best since joining camp, having needed to get up to speed as his conditioning was behind other players.
Midfielder Connor Metcalfe batted away a question regarding whether Volpato's late change of allegiance had been an issue within the squad.
Volpato is determined to make an impact.
"Obviously people are writing us off a lot because we're Australia, but I believe in the group, I believe in the coach, I think we've got a really good team, so hopefully we can shock a lot of people," Volpato said.
Striker Tete Yengi could also debut on Saturday (local time), Australia's final friendly before the World Cup.
The game's conditions mimic Australia's second group match against the United States on June 19 (June 20 AEST), with a midday kick-off and quick exit from the city afterwards.
"A good dress rehearsal, good last hit-out for players to get minutes in before the big dance in front of us," Popovic told AAP.
Switzerland also give Australia a strong European opponent to face before their June 13 opener against Turkey in Vancouver.
AUSTRALIA V SWITZERLAND:
Saturday June 6, 12pm (Sunday June 7, 5am AEST)
Snapdragon Stadium, San Diego
World rankings: Australia 27, Switzerland 19
Highest ever ranking: Australia 14 (2009), Switzerland 3 (1993)
Lowest ever ranking: Australia 102 (2014), Switzerland 83 (1998)
Coaches: Australia, Tony Popovic; Switzerland, Murat Yakin.
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