Devlin broke down in tears after finding out he had been named in the Australia squad for the tournament in Qatar alongside Tynecastle team-mates Kye Rowles and Nathaniel Atkinson.
The trio are among seven current and former SPFL players in the line-up with Celtic's Aaron Mooy, Hibs winger Martin Boyle, former Hibs and Rangers striker Jason Cummings, and Stoke defender Harry Souttar also included.
In footage shared by the official Socceroos Twitter account, boss Graham Arnold is seen making a phonecall to Devlin to inform him of his selection.
He asks Devlin how he is feeling before the Hearts star replies: "I'm beside myself.”
Arnold then asks: "I've got to touch base with you to see what you're doing the next few weeks, and if you want to come to Qatar?"
An emotional Devlin replied: "Don't, don't. Arnie you're going to make me cry. Thank you so much."
The Australia boss then explained his decision to include the former Newcastle Jets midfielder: "You don’t have to thank me, it’s the work you’ve been doing at Hearts and that desire and commitment. What we need is that little kicking Cam Devlin at the World Cup who's going to run like a lunatic for 90 minutes."
Devlin replied: "No Arnie that's f***ing out of control, thank you. The f***ing best news I've ever had in my life.
"And that kicking Cam Devlin will be in full force, let me tell you. I've never felt more ready for something in all my life."