FOUR State of Origin rookies are locked in a sprint race to a debut NSW Blues jersey.

Brad Fittler’s top adviser Greg Alexander has confirmed to foxsports.com.au the leading candidates for a spot in the halves are Nathan Cleary, Luke Keary, Mitchell Moses, and Luke Brooks.

All four men are under 27 years of age, and none of them have stepped foot on the Origin or Test stage before.

The other man in contention is veteran playmaker James Maloney, who already has nine Origin caps to his name and is the incumbent.

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Maloney was considered a lock for a starting spot in the halves before Alexander revealed this week selectors are worried about his defensive form.

A solid outing for Penrith on Thursday night will pour water on those fears somewhat.

But even if Maloney gets picked, NSW will enter Origin I with at least one half who has never experienced the game.

“It will be (one of those four),” Alexander said.

Alexander also revealed veteran five-eighth Blake Green isn’t being considered for NSW selection.

Green has never played Origin, but is an experienced head and has been in fine form for the Warriors, on the back of a stellar 2017 season with Manly.

He was being spoken about as recently as a couple of weeks ago, but will not be taking part in Origin I.

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“Blake’s going well, but we really haven’t spoken that much about Blake,” Alexander said.

Alexander would not spill the beans on which of the four rookies is leading the race as of now.

Cleary is running with the handicap of having played just one game of football in the past two months.

He made his return from a knee injury on Thursday night, and looked as solid as ever as the Panthers beat Brooks’ Wests Tigers.

Alexander was pleased with the performance of Cleary, but conceded two games may not be enough to earn him a NSW jumper.

“It was just good to see Nathan get back on the field,” Alexander said.

“Considering it was his first big injury, his first big knee injury, he looked confident and I thought it was a very confident return from him.

“That was the first thing, Nathan needed to get back on the field and feel confident on that leg. He looked good.

“But he hasn’t played Origin before ... he gets another game before the side is selected, but it’s a big ask to throw him into Origin.

“He didn’t goal kick last night, and I don’t know if we’ll need him to goal kick ... but there’s still a couple of things I’m sure he would love to do before he felt he was at the top of his game.

“Match fitness might take him a while. Origin games are 20 per cent quicker than what an NRL game is.

“The first thing was he got back on the field and did exactly what I thought he would do, and that was play well.”

Alexander also seemed pleased with the performance of Brooks, despite the fact he played in a losing team whose attack failed to fire.

Moses will line up for the Eels on Friday night, then Keary steps out for the Roosters immediately after.

All four men will have round 12 as their final audition for a Blues debut.