Fa'asuamaleaui was put on report for dangerous contact after he collected Koroisau in the face with his ball-carrying arm in the Titans' 28-12 win on Thursday night.
Koroisau went to hospital and will have surgery on Friday in Sydney. Wests Tigers coach Tim Sheens said he would miss at least six weeks of action and is out of the State of Origin series.
Fa'asuamaleaui is a certainty to be selected for the Maroons in game two of the Origin series in Brisbane on June 21, but the match review committee (MRC) will have their own say on Friday.
The Titans skipper was charged for dangerous contact against Canterbury in round 12 when he collected Reed Mahoney in the face with his forearm while in possession.
He was fined $1800 for a grade one offence on that occasion and cleared to play in game one of the Origin series in Adelaide.
Analysing the Koroisau incident on Channel Nine after the game, Maroons assistant coach Cameron Smith said that it was a different style of case to the incident with Mahoney.
"Looking at the incident, I am trying to find what is illegal about the action," he said.
"If you actually see the bump which he makes on Api Koroisau, it is with his ball-carrying arm … his right arm. Whereas you look at the last time he was charged, a few weeks ago, and it was when he led with his left arm into Reed Mahoney.
"I don't know what he is meant to do with that ball-carrying arm. Is he meant to make it disappear?"
After the clash against the Tigers, the Titans skipper defended his technique while running with the ball. He said he'd been taking the same approach since he came into the NRL and that sometimes players "put their head in the wrong position".
"It is a contact sport," he said.
"I am running as hard as I can. He is getting up to try and stop me and came off second best. I am hoping he is alright and I am hoping I am alright too."
He was asked whether he was concerned he would miss the Origin showdown in Brisbane.
"I think it is similar to the other week (after the Mahoney incident). It is just the media making me more worried than anything, just trying to build it up," he said.
"I hope I get selected (for Queensland) first, and if I am I hope I am in the team."
If he's not, or even if he is, Fa'asuamaleaui said fellow Titans prop Moeaki Fotuaika deserved a recall to the Queensland team for the first time since 2021.
The Maroons are already without key forwards Jai Arrow (syndesmosis) and Tom Gilbert (shoulder surgery) for the rest of the series and Fotuaika is one of at least seven players in contention.
"I think he has been our best player mostly every week," Fa'asuamaleaui said.
"Obviously there have been some injuries and I am hoping his name is tossed up. He is the guy that does all the little stuff and works hard. I am hoping he gets picked in the team."
