Luai was desperately missed by the Tigers in their 28-10 loss to Manly on Friday night, after being ruled out on the morning of the game.
The 28-year-old skipped training on Thursday with an infection from a boil, before needing to be hospitalised with fevers.
The four-time premiership winner took to Instagram on Saturday to share a story that said "God, thank you for waking me up today", with a caption that read "back up and go again".
NSW coach Laurie Daley will name his team for the July 9 Origin decider on Sunday, and it is expected Luai will be picked in the No.6 jersey.
AAP understands the Blues would be happy to bring Luai into camp if he was not ready to train, and would be fine with him not taking to the field in their first session on Wednesday.
But NSW officials would want him to be fit for Thursday's training run, which usually serves as an opposed run where preparations ramp up for game day.
The Tigers painted an optimistic picture over Luai's health on Friday night, believing he could have played if the game was later in the weekend.
"I am pretty sure he will be OK for NSW if they pick him," coach Benji Marshall said on Friday night.
"He got an infection yesterday and didn't come to training. He said he was going to be all right to play.
"And then he went to hospital and had fevers and the infection got a lot worse.
"If it was another 24 or 48 hours Jarome would have been right to play. But he wasn't good for today."
But while the Tigers missed Luai in attack, his availability for the Blues at Accor Stadium in a week and a half is crucial.
Mitch Moses is still out with a calf injury after being hurt in camp for game two, prompting Luai's return to the side.
Fellow half Nathan Cleary will be fit to play, after kicking freely in general play in Penrith's win over Canterbury on Thursday night with his sore groin.
Cleary is yet to resume goal-kicking after hearing a pop in his groin on the day before Origin II, and has avoided questions on whether he will in Origin III.
NSW have already had Matt Burton as back-up half for Origin II, and he appears the most likely to be on standby for Luai and Cleary next week.
Serious concerns also remain around winger Brian To'o, who had scans on his left knee on Saturday afternoon.
To'o hurt his knee in the Panthers' win on Thursday night, and left CommBank Stadium with ice on it.
"I'm still walking, that's the main positive sign," To'o said as he left the ground on Thursday night.
"I think it might've happened during the game. Either way I'm all good ... It's good."
If To'o is unavailable for the series decider at Accor Stadium, Canterbury winger Jacob Kiraz would be the clear front-runner to replace him.
Kiraz was in line to start the series for the Blues before a calf injury ruled him out. He also came in as cover when To'o battled a hamstring injury before Origin II.
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