James Tedesco head knock biggest blow for New South Wales

In a State of Origin series marred by concussions, James Tedesco's heavy head knock in Wednesday's night decider proved the most crucial blow for NSW.

Tedesco lasted just 20 minutes at Suncorp Stadium, assisted from the field after his head collided with Josh Papalii's knee on a kick return.

Five-eighth Cody Walker followed later, the victim of friendly fire and taken from the field in a medicab with five minutes to play.

But it will be Tedesco's injury that is bound to attract the most attention from the 20-14 loss.

The incident prompted criticism of Queensland forward Jai Arrow, who roughed Tedesco up and pushed his head after he'd already gone to ground.

"That's just not needed," Andrew Johns said in commentary.

"The game's hard enough as it is without that rubbish coming into play."

With no extra backs on the bench, Tedesco's blow - and Walker's 55 minutes later - couldn't have been any worse scripted for the Blues.

Clint Gutherson reverted to his usual position at fullback from centre, while Isaah Yeo was forced to come into the centres.

But NSW desperately missed their No.1 man.

After he scored their first try before he went off, they could have desperately done with his speed and power around the ruck.

And while they'd usually look to their captain as a game breaker, Gutherson finished the night with just 70 metres compared to Tedesco's 473 from the first two games.

It comes at the end of a series headlined by concussions.

The NSW Rugby League received a formal warning from the NRL after Game I when original captain Boyd Cordner was allowed back onto the field after a knock.

Cordner had passed an off-field HIA, but the NRL claimed he had already exhibited signs of concussion on the field and should have stayed off.

The Kangaroos Test captain then made the decision to pull out of the rest of the series after repeated head knocks this year.

Queensland then lost their strike weapon Cameron Munster just two minutes into Origin II, after he too suffered a concussion.

It prompted ongoing debate on his fitness for the decider before he passed all required protocols to star in Queensland's Suncorp Stadium win.