Luke Keary’s chances of a State of Origin debut could be in tatters after being knocked out in Sydney Roosters’ shock 38-12 blowout loss to Newcastle.

Kalyn Ponga and Mitchell Pearce once again starred in a five-try romp to claim a fifth straight victory that will reverberate around the NRL.

Keary was momentarily prone after the back of his head bounced into the turf following a heavy Daniel Saifiti tackle in the eighth minute on Friday night.

It is the second time in five weeks the Roosters star suffered a concussion, in addition to two separate head knocks last year.

Even if picked by Blues coach Brad Fittler, Keary will likely sit out a large chunk of NSW’s preparations.

“He’s not in a great condition. I took your advice (Phil Gould), you don’t pick it too early. He’s feeling a headache, let’s put it that way,” Fittler said on Channel Nine.

“I think my biggest concern is his health at the moment. I’ll take advice from doctors and medical staff.

“If he was going to be picked at five-eighth, there’s a couple of handy replacements who are in good form.”

Already without a rested Cooper Cronk, Keary’s early exit left the defending premiers rudderless against the hottest team in the competition.

Not even a syndesmosis injury to Danny Levi dampened a Knights outfit that had the 25,929 McDonald Jones Stadium crowd rocking from start to finish.

Keary’s attempted offload landed directly in the hands of Hymel Hunt for the game’s first try, before James Tedesco hit back with a quick-tap four-pointer.

But that was as close as the Roosters got, with Ponga and Pearce setting up tries for each other in the space of four minutes for a 22-6 halftime lead.

It is the sixth straight match Ponga has crossed the stripe, and fifth for Pearce.

A Connor Watson try minutes into the second half all but ended any thoughts of a comeback, before Edrick Lee completed the rout late.

There was a flashpoint midway through the period when a heavy Jared Waerea-Hargreaves shot on Ponga ended in a head injury assessment and minor melee.

Ponga eventually returned to the bench but failed to re-enter the match.

The win lifts the Knights into fifth spot – the highest the club has been this deep into a season in six years – while the Roosters will remain third.