Rugby League boss Peter V'landys says it is "quite obvious" that Blues forward Isaah Yeo "should have come off" after suffering a head knock during State of Origin I, but the process that cleared him to play on was followed correctly.

Yeo appeared to be injured in the game's first tackle on Wednesday night, having been thrown backwards onto the ground following contact with the shoulder of a rampaging Josh Papali'i.

The Panthers lock then appeared to show symptoms related to concussion, stumbling back into the defensive line, where he was briefly supported by Tariq Sims, before making the next tackle.

Maroons half Cameron Munster, who pointed and shouted at his wobbling opponent to attract the attention of the officials, later said the incident made him feel "sick".

"It wasn't rocket science," he said. 

Yeo, who said after the match that he was fine, was checked by the Blues trainer on the field and again at half time but was cleared of concussion.

Yeo played 53 minutes in the match, making 10 hit ups in attack and 30 tackles in defence as the Blues were beaten 16-10.

Yeo will not play in Penrith's NRL match against Newcastle on Sunday.

Speaking on Radio 2GB on Friday, V'landys said that although he thought Yeo should have come off, he was satisfied the independent doctor in the bunker followed the proper process.

"I think he should have come off," V'landys said.

"I'm not a doctor, but [the independent doctor in the bunker] immediately let the trainer know on the field, the trainer did do an assessment and he believed that he didn't need to come off.

The independent doctor told the Blues' team doctor that Yeo was a category three, meaning there were no clear signs of concussion, which meant it was up to the NSW trainers to assess him on the field.

Blues doctor Nathan Gibbs told News Corp he was only shown footage of the initial contact, not of Yeo stumbling, however he said the bunker doctor "knows what he is doing" and has "all the camera angles".

"That is how the system works well. We're not concerned about that aspect of it," he said.

"The people who have all the camera angles can make a better call. In the end, they make the call." 

V'landys said: "The right process was followed."

"They immediately let the trainer know, the trainer did an assessment, they assessed him again at half time, he showed no symptoms," V'landys said.

"The doctor in the bunker may knew more than we did, but on the vision, it certainly appeared that he should have come off.

"That's one of the reasons we have the independent doctor in the bunker."

"We're very serious about concussion and the welfare of the player.

"Our actions in the last two years have shown that.

V'landys said head injury rates had reduced "dramatically" this season and he praised players for adjusting to the new focus on lower tackling.

"We want to make sure the player, when he leaves the game, leaves with all his faculties and has quality of life," he said.

"We want to eradicate hits to the head.

"We're going to continue that path, we're going to make the game safe, in particular, around the head."