Alex Gersbach, Stefan Mauk and Awer Mabil might have missed out on the Socceroos squad but they've still been called up for national team duty.
The former A-League flyers head a 22-man 'Australian development squad' that will gather in Spain next week for underage international friendly matches with Austria and Finland.
As reported first by The World Game, the nine-day camp will be led by Olyroos coach Josep Gombau and is designed to prepare them for the rigours of international football.
"A lot of players in this squad we haven't worked with before so this camp allows us to bring them in and expose them to the national team setup and see the levels they are at and how they are tracking," Gombau said.
While the development squad are in Murcia, the Socceroos - including underage bolter Riley McGree - will contest 2018 FIFA World Cup qualifiers against Iraq and United Arab Emirates.
The group also includes Melbourne Victory loanee Thomas Deng, currently at Dutch club PSV, and Anthony Kalik, who moved from Central Coast to Hadjuk Split of Croatia last year.
Fringe Socceroo Chris Ikonomidis is also in the squad, as is the brother of first-choice national team striker Tomi Juric, Deni.
The sole current A-League representative is Newcastle Jets defender Nicholas Cowburn.
"We need to try to know every single Australian player with potential and work hard to bring them in," Gombau said.
Callum Elder, of English Premier League club Burnley, and Ajax Amsterdam-based Sebastian Pasquali have been ruled out with injury.
SOCCEROOS DEVELOPMENT SQUAD
Panos Armenakas (Udinese, Italy - 18 years old), Jake Brimmer (Liverpool, England - 18), Cameron Burgess (Bury, England - 21), Nicholas Cowburn (Newcastle Jets, Australia - 22), Thomas Deng (PSV Eindhoven, Netherlands - 19), Alex Gersbach (Rosenborg, Norway - 19), Thomas Glover (Tottenham, England - 19), Jordan Holmes (Eastbourne Borough, England - 19), Ajdin Hrustic (Groningen FC, Netherlands - 20), Chris Ikonomidis (AGF, Denmark - 21), Deni Juric (Hajduk Split, Croatia - 19), Anthony Kalik (Hajduk Split, Croatia - 19), Josh Laws (Fortuna Dusseldorf, Germany - 19), Jordan Lyden (Aston Villa, England - 21), Awer Mabil (Esjberg, Denmark - 21), Stefan Mauk (NEC, Netherlands - 21), Ashley Maynard-Brewer (Charlton Athletic, England - 17), Danijel Nizic (Morecambe, England - 21), Aiden O'Neill (Oldham Athletic, England - 18), Con Ouzonidis (Everton, England - 17), Milislav Popovic (FC Koln, Germany - 20), Thomas Prinsen (PEC Zwolle, Netherlands - 17).