Former Socceroos boss Ange Postecoglou says it's a no-brainer for his successor Bert van Marwijk to take both Daniel Arzani and Tim Cahill to the 2018 FIFA World Cup.
The youngest and oldest members of the Socceroos squad are in Turkey in a pre-tournament camp that doubles as the final selection process for Russia.
Three squad members will be cut adrift ahead of the World Cup, with some speculating that the current and former Melbourne City players could be in the gun.
Arzani, 19, is yet to be capped and is untested outside of the A-League.
Cahill, 38, has tallied barely an hour of match minutes at club level since walking out of City back in December
But in a squad lacking in goal threat, Postecoglou said both Arzani and Cahill must be a part of the Australia squad to take on France, Denmark and Peru.
"You take them both," Postecoglou told Melbourne radio station SEN.
"There shouldn't be a debate about Arzani ... we have very few players like Daniel Arzani.
"With what he's shown so far and the potential that he has, whether he kicks on from here or not is up to the kid himself.
"To not give him that experience, that exposure, for Australian football when we have so few like him, it's an opportunity missed."
Postecoglou managed the Socceroos to the World Cup, navigating a marathon 22-match qualification process, but resigned afterwards citing the pressures of the job.
Now Japan-based, Postecoglou said back then Cahill "was definitely going to go".
"Since then there has been eight months and he hasn't played a lot. Knowing Tim ... he still would be in very good condition.
"There still isn't a lot of goal-scoring threats there. Tomi Juric hasn't played a lot in recent times so you have to take (Cahill).
"Timmy is always the one that I had (as a) kind of 'break the glass if needed' and I don't think that's changed."
Postecoglou retains a stake in Australia's fortunes in Russia, with defender Milos Degenek in his squad at his J-League club Yokohama F.Marinos.
The club is 13th in league, which has paused for the World Cup.
"We've had a pretty intense period, we've had 15 games in about seven weeks," he said.
"Things are going okay here. Results haven't been spectacular but I'm slowly making in-road in terms of the way I want the team to play."
As for his own World Cup plans, Postecoglou said they involved beer.
"I'll plonk myself up at a bar somewhere hopefully on an island in Greece and cheer the boys on and then get back to work here and make a success here at Yokohama," he said.