Arzani's run to the Socceroos squad has been spectacular and unexpected since making a first start for Melbourne City last August in the FFA Cup.
The raw talent has just 16 starts in his professional career and made a debut for Australia off the bench in Friday's 4-0 friendly win over Czech Republic.
Arzani is joined by Kylian Mbappe, of group stage opponents France, and England defender Trent Alexander-Arnold as one of just seven teenagers at the tournament.
Another of Australia's opponents, Denmark's Christian Eriksen, was the youngest player at the 2010 World Cup at 18 years and four months of age.
At the other end of the spectrum, striker Tim Cahill is the fourth oldest player to be heading to Russia.
Australia's all-time leading scorer, who mentored Arzani at City prior to his departure from the A-League, is gunning to play and score at a fourth World Cup.
That accomplishment would put the 38-year-old on a par with legendary Brazilian Pele and German pair Uwe Seeler and Miroslav Klose as the only men to score at four tournaments.
But Cahill is a fair way short of the oldest player in Russia. That honour belongs to Egypt captain and goalkeeper Essan El-Hadary, who will debut at the World Cup as a 45-year-old.
The gloveman was just 17 when the Pharaohs last qualified for the tournament.
Mexican defender Rafael Marquez, at 39, and Russia's Sergey Ignashevich are the only other men born in the 1970s to make it to the 2018 event.
TEENAGE KICKS: YOUNGEST PLAYERS AT THE WORLD CUP
19 years old - Daniel Arzani (Australia), Kylian Mbappe (France), Achraf Hakimi (Morocco), Francis Uzoho (NIgeria), Trent Alexander-Arnold (England), Moussa Wague (Cameroon), Jose Luis Rodriguez (Panama).
GEN X-ERS IN ACTION: 1970s BABIES AT THE WORLD CUP
45 years old: Essan El-Hadary (Egypt)
39 years old: Rafael Marquez (Mexico)
38 years old: Tim Cahill (Australia), Sergey Ignashevich (Russia)
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