The Dragons forward was in good spirits on Monday less than 24 hours after a sickening head clash with ex-teammate Josh Dugan which even had Frizell unsure of what he was asked during his head injury assessment.

"I just can't remember any of [the questions] now you've asked me," a smiling Frizell told the Sydney Morning Herald on Monday.

"I didn't remember who the collision was with until 'Duges' [Josh Dugan] came into the room afterwards to check on me. I saw a nice little gash across his head and realised it was him.

"And I forgot Freddy [NSW coach Brad Fittler] came in to check on me. I was a bit spacey. I'm fine now. It was more how I felt [on Sunday] night with the headaches and all that."

The NRL has written to both the NSWRL and Queensland Rugby League to explain the use of the brain bunker, a remote facility used to monitor potential head knocks in real time. It can then relay information to on-field medical staff and doctors, which can be used to evaluate a player's suitability to stay in the game.

The use of independent concussion spotters stationed in the crowd, which has been in use for previous Origin series, will be scrapped.

"The states have been given written instructions about how the bunker will work," NRL head of football Graham Annesley said.

"It's absolutely and completely thorough. It's cutting edge in world sport to have these sorts of things monitored live so doctors can be instructed to review incidents. It's taken a while to get it to this point, but we introduced it at the start of the year so we don't need people live at the venue other than the people in the tent. If there needs to be any conversation between the doctor when he comes to look at the video and the spotters in the bunker that can happen as well on a particular aspect of play."

Fittler entered the dressing-room at half-time on Sunday to check on Frizell.

After realising Luke Keary was in a bad way on Friday night, Fittler said Frizell was not much better on Sunday.

"Obviously watching the game I was nervous for him and worried," Fittler said. "When I spoke to him, I don't think he knew who I was. He had that stupid smile going and talking about seeing the doc to go back on.

"Given the year he has had with the severed teste, the [poked] eye and now the concussion, there will be protocols we follow and the actual rest for him will be great. He'll be allowed to do stuff by Friday."

Frizell admitted he was not in the greatest form coming into an Origin campaign and had not been helped by the run of injuries.

The lacerated testicle he suffered in a freak accident happened in week one, then the poke in the eye occurred against Parramatta earlier this month, forcing him from the field because of poor vision.

Frizell was one of the first players pencilled in by Fittler when he was asked about selections a few weeks ago.

"It hasn't been the ideal start for myself and I haven't been in this position before with so many different injuries happening so frequently,'' Frizell said.

"I'm not in the best form coming into Origin, I know that, and that could be due to all these hiccups. But I've been on this stage before and know what's needed and I will be able to produce what I've been able in the past. The teste is all healed. There were complications that could have happened, but I made sure I saw the right people and that everything was OK. I don't have to wear the [protector] any more, but I still do, just for peace of mind."

The corresponding day in Origin camp last year was a celebration for St George Illawarra with Jack de Belin, Paul Vaughan and Tariq Sims all given the nod for the squad alongside seasoned campaigner Frizell.

The circumstances surrounding de Belin have hung over the Dragons since the start of the year and Frizell said: "You'd love to see him a part of this team, but things have happened, he's not able to play. But he'll be cheering for us and wishing us the best."