Cristian Volpato pledges allegiance to Australia just days out from Tony Popovic's World Cup selection announcement

The final audition to make Australia's World Cup team is just over 24 hours away, with coach Tony Popovic ready to cut four of those still in his 30-player training camp.

Popovic will lock in and unveil his 26-man Socceroos team on Monday, June 1 - the deadline date for all participating nations to have their squad lists submitted by.

But while fans have been given a glimpse into the style of play that Popovic expects from his team, there are still some questions marks lingering of certain positions.

READ MORE: Crichton axed as Joey makes sweeping Blues changes

READ MORE: Arrow and his fiancée open up after devastating diagnosis

READ MORE: 'Confusion' as key Essendon staff quit following Scott sacking

The late arrival of Cristian Volpato to training camp is one of the bigger surprises for the Socceroos, given he looked set to pledge his senior international allegiance to Italy.

The 22-year-old had represented Italy at youth level in the past, but having been born and raised in Sydney, he was eligible to represent Australia at a senior level.

Popovic had visited Volpato earlier in the year to work out whether he would be fit to represent Australia, however, he admitted he would not "sell the shirt" to the young star.

With Italy failing to qualify for the World Cup, Volpato has seemingly made up his mind. On Friday, Football Australia revealed they had lodged paperwork to FIFA to confirm that Volpato would represent the green and gold at a senior level.

Volpato would be a desirable candidate to replace the injured Riley McGree, who was ruled out of the World Cup last week after suffering a hamstring injury.

Awer Mabil will be battling against Volpato to be in the midfield, despite spending a longer duration in camp than the national team's new recruit.

Aside from Volpato's late arrival, the process of elimination has been swift for Popovic, but it is clear that one of his four goalkeepers will be hit by the axe come Monday.

Mat Ryan has been the starting goalkeeper for the green and gold over the past three World Cup campaigns and will likely hold that role again. Paul Izzo could challenge the Australian captain for the No.1 jersey, but he will likely be the second-choice keeper.

That leaves a battle between Patrick Beach and Joe Gauci to be the third-choice keeper. Gauci has not appeared in a Socceroos squad since October last year, but he has been delivering an impressive run of performances with Port Vale in the English League One.

As for Beach, he appeared to have overtaken Gauci, 25, to grab the third goalkeeper spot since making his debut for the national team in November last year. The 22-year-old Melbourne City talent will be hoping to beat out Gauci for a spot at the World Cup.

Popovic has 11 defenders in training camp at this point in time, with question marks lingering over Milos Degenek, Jason Geria and Kyle Rowles.

The trio have been regulars in Popovic's squad - it is going to be a tough call.

It is expected Popovic will view Kai Trewin as a fit back-up for Jacob Italiano at right wing-back. Nestory Irankunda, Martin Boyle and Mathew Leckie, meanwhile, are all staples up front. Mohammed Toure all but set to be the nation's starting striker.

Brandon Borrello and Tete Yengi will likely battle it out for the final spot up front, with the latter only just earning his first-ever call-up into the national team camp this month.

Fans will have to wait until Monday to learn who has been named in the team.