Jarome Luai will replace Mitch Moses as NSW's five-eighth for the second State of Origin match after a calf strain dashed Moses' hopes of playing.
Moses pulled up sore while running the ball during a training session at NSW's Blue Mountains camp on Thursday, injuring the same calf that troubled him earlier this year.
The Blues have sent Moses for scans on the injury that delivers a blow to their hopes of sealing a series victory by winning Origin II in Perth on Wednesday.
"It's terrible, isn't it? Mitch played really well in game one," said Blues coach Laurie Daley.
"We're unsure of how bad it is but he won't be any good for Wednesday with the short turnaround."
Daley called Luai on Thursday to ask whether he would be available after being beaten for selection in the series opener by Moses.
Luai, who had just finished on the training paddock at Wests Tigers, answered Daley's distress call to reunite with former NSW halfback Nathan Cleary in the halves.
It's the second time in as many years that injury has forced the Blues to turn to a player they initially snubbed, with James Tedesco coming in for Dylan Edwards to play fullback in last year's series opener.
"Luai handled it (the initial rejection) with such class and he said if I needed him, he'd be ready to go," Daley said.
"So when I rang him, he said, 'Sweet, I'm ready to go'. That filled me with confidence."
Luai played five-eighth in all three games of NSW's 2024 series win and has featured alongside NSW halfback Cleary at Origin level six times already.
The pair also won four consecutive NRL premierships together at Penrith before Luai joined the Tigers this season.
"Back playing together, there'd be an energy and a synergy there," Daley said.
"(Luai) played there last year, has got a good combination with Nathan and he's that left-side player.
"He'll do a fine job."
The NRL has already granted the Blues an exemption to bring Luai into the team from outside the 20-man squad that Daley had named on Tuesday.
Luai's call-up means Canterbury five-eighth Matt Burton, considered the other contender to replace Moses, will remain 18th man.
Daley defended the call to once again overlook Burton, who will watch from the sidelines as NSW's replacement player for a fifth time in seven Origin games.
Burton's ability to cover the outside backs and halves has made him a favoured choice for the emergency role.
"(Burton) would be disappointed, you'd want him to be disappointed, but he gives us a bit more versatility in that 18th-man role," Daley said.
"He can play a few more positions. I just think Jarome and Nathan's combination, they've had so much success."
Luai will arrive at the Blues' team hotel in Leura on Thursday afternoon, expected to bring his trademark high energy to a squad reeling from the injury.
"He'll walk in and everyone will feed off his energy," Daley said.
"I don't think anything fazes Jarome. He's always up for a challenge and the bigger the challenge, the better he goes.
"He's a guy that thrives in this environment. It's not an issue for him so it shouldn't be an issue for anyone else."