Lucas only learned he would be coming into the Blues' starting side for the second State of Origin match on the morning of Laurie Daley's public team announcement.
The Newcastle star had presumed he would reprise his role as 20th man at the MCG on June 17, but now replaces the axed Haumole Olakau'atu in the second row.
Lucas made a mad rush to call his loved ones and tell them the good news on Tuesday morning ahead of the squad's team photo and media call.
"It's a real honour, I'm very grateful that 'Loz' has put his trust in me," he said.
An athletic and skilful ball-runner, Lucas has enjoyed a great season with the resurgent Knights, whom he first joined as an 18-year-old in late 2018.
Lucas had grown up in Albion Park, just south of Wollongong, and was in the Dragons' Illawarra Steelers feeder system as a teenager.
But after playing SG Ball in 2018 alongside the likes of Jayden Sullivan, Mat Feagai and Aaron Schoupp, Lucas was told his playing future lay elsewhere.
"To be honest, they (the Steelers) weren't that keen and there was an opportunity up there in Newcastle," Lucas said.
That opportunity was an offer to play under coach Scott Dureau in the Knights' under-20s team for 2019.
So, a few weeks after finishing high school, 18-year-old Lucas packed his bags and moved up to Newcastle on his own to chase his dream.
"I thought I'd just take a risk and head up there and leave everyone and get out of my comfort zone. I'm that glad I did it now. It's definitely paid me back," he said.
Lucas said he found it a little disheartening at the time not to have been wanted in the Dragons' system.
"I suppose anyone would," he said.
"It's a crazy journey but one that I wouldn't change for the world. It landed me up there in Newy and I'm that happy up there now."
Lucas and fellow NSW second-rower Hudson Young both typically start on the left at club level but the debutant is likely to revert to the right next Wednesday.
But having played lock, centre and in the halves as a youngster, Lucas is used to being adaptable.
"I'll get some reps there on the right and I'll be good to go," he said.
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