Junior All Whites coach Darren Bazeley said he is in negotiations with Marseille, who are nearing the end of their season, over exactly when Tuiloma will be released, but hopes he will be able to play in at least one of their remaining two friendlies against Honduras and Austria before the tournament starts on May 30.
"The captaincy is something we thought about for a while but Bill is the most senior player that we have, he's a regular All White, is in a great environment and when I've spoken to him I've been very impressed with his maturity and leadership within the All Whites camp," said Bazeley.
"He can really help drive our culture and philosophy and he has a lot of respect from the players."
Tuiloma is one of 10 players in the squad who have been part of the senior New Zealand setup in recent months, including six players who have played for the All Whites.
Six of the squad of 21 are based overseas and Tuiloma is joined offshore by Jesse Edge (Italian club Vicenza Calcio), striker Monty Patterson (Ipswich Town FC) goalkeeper Nik Tzanev (Brentford FC) and United States-based Cory Brown (Xavier University) and Stuart Holthusen (Akron University).
The tournament is expected to reach 170 million television viewers across 100 countries and football governing body Fifa is hoping 500,000 fans pass through the gates over the course of the 52 games.
"I think the players are gradually getting it, just how big of an opportunity this is, and how much pressure and expectation will be on them," said Bazeley.
"They're starting to realise that now. I think the public won't really get it until it starts and will then say 'oh this is a really big event and there are unbelievable players here'."
The Junior All Whites open the World Cup against Ukraine, before facing youth powerhouse USA and Myanmar.
"Myanmar are probably the team we are expected to do well against, but, because they are our third game, we can't target that, because our tournament could be over by then.
"If we pick up no points from our first two games, it's over.
"So we're targeting the opening game against Ukraine. But all three will be tough opposition," said Bazeley.
All Whites defender Deklan Wynne said it had been a bittersweet week for the team, who were all thrilled about getting selected for the adventure ahead, but also sym-pathetic with those who had played for Wanderers SC in the national league for the past two years before getting cut at the final hurdle.
"To see some of the guys crying yesterday when they got cut was quite heartbreaking, and you could see just how much it meant to everyone," said Wynne. "We've been training together for two years so it has been quite a long process."
Men's FIFA U-20 World Cup 2015 Squad
Goalkeepers
Damian Hirst - Wanderers SC, NZL
Oliver Sail - Wellington Phoenix, NZL
Nik Tzanev - Brentford FC, ENG
Defenders
Sam Brotherton - Wanderers SC, NZL
Cory Brown - Xavier University USA
Jesse Edge - Vicenza Calcio, ITA
Brock Messenger - Wanderers SC, NZL
Adam Mitchell - Wanderers SC, NZL
Deklan Wynne - Wanderers SC, NZL
Midfielders
Andre de Jong - Wanderers SC, NZL
Moses Dyer - Wanderers SC, NZL
Te Atawhai Hudson-Wihongi - Wanderers SC, NZL
Clayton Lewis - Wanderers SC, NZL
Matthew Ridenton - Wellington Phoenix, NZL
Bill Tuiloma (capt) - Olympique Marseille, FRA
Forwards
Noah Billingsley - Wanderers SC, NZL
Andrew Blake - Wellington Phoenix, NZL
Stuart Holthusen - Akron University, USA
Monty Patterson - Ipswich Town FC, ENG
Alex Rufer - Wellington Phoenix, NZL
Joel Stevens - Wellington Phoenix, NZL
