Stephen Carmichael headed the New Zealand contingent: the young striker made history last year when he scored a hat-trick at the Under-17 World Cup in Mexico.
"That experience motivated me even more to achieve my dreams," said the softly spoken Central United (Auckland) player. "It would mean everything to get through."
A national team-mate was Reece Lambert, who playedtennis and touch before settling on football.
"This week is is going to be all about attitude," said Lambert. "You have to always want to be on the ball. Also, you want to perform - you don't want to let Danny down after he has put faith in us."
Iraqi-born Van Elia had his brother to thank, after his sibling signed him up for the Wellington trial. He had come to New Zealand via Jordan as a refugee and didn't take up football until he was 11.
"I'm lucky - I don't really get nervous," he said before the trials. "All I know is that this is probably one of the best opportunities I've ever had."
Speedy winger Kojo Norku was well known to Hay. "He always used to come over to train on our fields [at Sacred Heart College] after school," recalled Hay. "Often I had to kick him off but I admired his dedication."
Born in Botswana, Norku learnt his football in Yorkshire, England, before his father's engineering job brought the family to New Zealand four years ago.
"I didn't speak for about 30 seconds when Danny told me I was selected," says Norku, "and since then, my parents have started to take my football goals more seriously.
"Before, they thought I was dreaming. Now I want to show them what I am."
Apart from the manicured pitches and incredible facilities, Cameron Martin of Papakura was loving the PlayStations in every room and the canteen's huge - but healthy - buffet.
"You can already feel the New Zealand-Australia rivalry," said Martin. "I love thechallenge."
The final Kiwi was Ahmed Al-Sharnsi, who emigrated to New Zealand from Iraq at age four. Tight finances meant he didn't join a club until well into his teens but he subsequently made the wider squad for the Under-17 World Cup.
"This week you have to shine," said Ahmed. "It's all about being noticed."
* * *
And so it began. Thrown together as strangers, combinations started to gel during the squad games. The football was typical trial fare, some players doing too much while others seemed afraid to get involved.
With the selectors poised with their clipboards, everybody yearned for the red circle or asterisk, rather than a cross.
The camp attracted scouts from Melbourne Heart and Western Sydney Wanderers and representatives of Adelaide United and Queensland Roar.
The AIS is slightly dated but remains a formidable facility. Photos of Aussie sports legends line the halls and walls: you walk along Glenn McGrath Way or John Eales Lane. The bookshop features More Than Sunshine and Vegemite - Success the Australian Way and What Doesn't Kill You ... Lessons from Sporting Despair.
In the huge canteen, gymnasts, cyclists and weightlifters share tables heaving with food. Part of the buffet resembled a giant self-service Subway, without the (fatty) condiments. Photos were forbidden inside, we were told, for fear of other countries copying the winning recipe.
Canberra seems a perfect location for deep focus and hard training - there's little to distract sporting types. "There is not much to do here," said one taxi-driver, who struggled to find positives about life in the Australian capital aside from lack of traffic and "not much crime".
Back at the AIS, the Kiwis impressed in individual testing. Norku was a standout in the speed work and others made their mark in the endurance sphere.
On the second day Elia scored one of the goals of the week, swerving past two defenders before unleashing a 30m rocket. Some timing.
Norku and Lambert struggled to get involved but Martin impressed with deft midfield touches and Al-Sharnsi was was an energetic presence. Carmichael was probably the standout, with intelligent runs, economic use of the ball and some pinpoint finishing.
During day two, Socceroos Bruce Djite and Mitch Nicholas visited the camp to give encouragement and advice. Djiite pointed out he had missed out on age-group rep teams before making it with Adelaide while Nicholas was also a late bloomer.
The final day: another cold, crisp Canberra morning after the mercury had plunged to -4 overnight.
"This is your time to stand up, your time to stand out," Smith told the group before the final series of matches. "Make sure you have no regrets and make the most of it. We haven't made any final decisions yet."
Though there was tiredness, the football seemed more fluid as players had adapted to their team-mates. There was a notable lack of showboating, though one player signalled to the sky a la Cristiano Ronaldo after scoring a simple tap-in, suggesting he had been watching far too much Champions League.
* * *
After the last recovery session and another big buffet, the group assembled in the AIS theatre for the unveiling of the fortunate three. "This week, you have learnt the importance of workrate, attitude and mindset," said Hay. "This should be a stepping-stone to your future. Whatever happens, this should be a beginning not the end."
After some fanfare, the three winners were announced, with Carmichael among the top trio. The others were Matthew Billic, a flying left fullback who returned after missing the cut at the 2010 camp and Devante Clut, a clever midfielder not long past his 16th birthday.
"It was nerve-wracking - there are a lot of good dudes here," said Carmichael. "I was speechless when I heard my name.
"This is a chance of a lifetime and over there I need to show some real hunger. During the week I was just thinking about doing everything right and playing to my strengths. I felt good throughout the whole week; I had a few bad touches here and there but didn't drop my head."
"Stephen comes to life in the final third," reflected Smith, who has seen over 40 Socceroos since setting up the AIS national programme in 1985. "He has a soft touch and a good change of pace."
Carmichael has a few weeks to prepare before the Australasian trio fly to Barcelona in mid-August. While Clut called his parents almost straight away, Carmichael was planning to surprise his parents at Auckland airport.
