Queensland coach Paul Green says the jury is out on Jarome Luai ahead of the five-eighth's NSW Origin debut.
The Penrith No.6 has dominated the NRL alongside Nathan Cleary, earning him a maiden call-up to continue their partnership for the Blues in Townsville.
NSW coach Brad Fittler has backed the pair's ability to perform on the big stage, claiming they have already proven they can do it at Penrith.
But Green, a former Queensland halfback, says Luai will have to prove it at Queensland Country Bank Stadium.
"The answer is yes (he may get found out), but I'm not talking about Jarome there specifically," e said.
"Different people have made debuts where they've killed it, some guys have found that they just haven't got themselves into the game.
"How it pans out tomorrow for him I'm not sure ... I'm not saying he is or isn't going to be up to it, but it's a step up."
How Penrith's halves are able to adapt the Panthers' game to the State of Origin arena shapes as the biggest question to determine the fate of the opener.
The pair have won an incredible 46 of 48 games in the halves together since entering under-20s in 2015, including 11 straight to start the year at Penrith.
However the one thing they are yet to do together is a lift a trophy, with last year's grand final defeat to Melbourne the most notable loss.
Cleary is at least one of the most capped players in NSW's team, with his eight Origins making him the fifth most experienced player in the team at the age of 23.
But 24-year-old Luai is a rookie on the big stage, acting as part of NSW's squad last year without playing a game.
In comparison, rival halves Daly Cherry-Evans and Cameron Munster have 23 Origins between them and both are premiership winners.
"It's one thing Nathan and Jarome do very well, when the pressure is on they seem to get better," Fittler said.
"State of Origin is all about that.
"When it's challenging and tough that's when you stand up and show your courage. When it's easy, both teams are good enough to do that."
Luai was one of three Panthers to have his maiden NSW jersey presented to him by family at a team function on Sunday night in Sydney.
He also had his son Israel celebrate his third birthday in camp, cutting the cake with Fittler before the team left for Townsville.
"It was very emotional and a great night for the team," Fittler said.
"Sometimes you need to go and speak to families and what it means to me.
"Once you're in the bubble everything is so intense and the preparation is so serious. It was nice to see the families and get their feels for it."