What Bert Said: Caltex Socceroos boss on bolters, unheralded inclusions

Caltex Socceroos boss Bert van Marwijk hinted at Daniel Arzani's "something extra" as the reason for picking Australia's youngest ever FIFA World Cup squad member.

Arzani, 19, could yet be the youngest player at the entire tournament after Van Marwijk named him in a final 23-man squad that features an exciting blend of youth and experience.

Sunday's announcement confirming Arzani's inclusion caps a remarkable rise for the teenager, who had made just six senior professional appearances - all as a substitute - prior to this season.

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But a consistent showcase of his eye-catching touch and dribbling ability in Melbourne City's run to the Hyundai A-League Semi Finals turned heads and has now created Caltex Socceroos history.

Speaking with reporters early Monday morning (AEST), van Marwijk also offered thoughts on his wider squad selection and the tough process of settling on the 23 who will head to Russia.

Here are Bert van Marwijk's comments following his selection of the Caltex Socceroos' FIFA World Cup squad...

ON THE UNLUCKY PLAYERS

"They are always the hardest decisions. I've had the experience a few times. I told them when we started that moment would come. You have to think as a professional but it's always an emotional day for everybody."

ON DANIEL ARZANI

"The fact he is with the last 23, that says enough. He's improving but he has to learn a lot. He is a player with something extra."

ON JAMIE MACLAREN

"I got him [into camp] because of the injury of Tomi Juric. He came and I'm satisfied about him. He's a typical player who always gets a chance [to score]. It's difficult for him because he was already on vacation for eight or nine days. I wanted to give him a real chance, a week.

"He had to train very hard from the first moment. We train very intensively and [often] two times a day. It was really difficult for him, not really fair for him. But he made a good impression. I think I need him."

ON THE SQUAD COMPOSITION

"Of course I look at those problems. But defensively I think we have enough players. [What is] very positive is the development of Josh Risdon. I have another two players in the squad who can play that position.

"We have enough central defenders and the defensive midfield players are the same. And now I have options in front with several types of centre-forwards, number nines. Andrew Nabbout can also play on the side and the number 10 position. I have more players who can play in more positions."

ON PERCEIVED INEXPERIENCE

"I think everybody must be very happy this team has a few more new players."

ON IRVINE MISSING TRAINING

"It's not really a problem. He has a little bit of a problem with his hamstring, but not really. He will train tomorrow [Monday]."