Mbye may still be living only because of the freak coincidence that it was the team's doctor who first found him on Friday morning.
The Courier-Mail has reported extraordinary details of the quick-thinking that saved Mbye's life.
The report outlines how Mbye called Hislop to his hotel room, complaining of a breathing issue during the team's day-off around 10.30am on Friday.
By the time the medical chief got there, Mbye was slumped on the floor outside his room and struggling to breath.
Hislop then administered an injection of epinephrine to his upper leg to save his life.
Mbye was close to death after his airways closed up in the frantic moments before Hislop was able to jump into action.
He was then monitored by staff for the rest of the morning before making the extraordinary decision to participate in the team's training session just hours after having his life flash before his eyes.
According to reports, the QRL was able to contact Mbye's wife and his three children back in Sydney on Friday to assure them that the star utility was making a full recovery.
Mbye has told the team he has no allergies and has never previously suffered an anaphylactic shock.
Queensland released a statement on Saturday to announce Mbye will play in the second game of the Origin series.
The QRL also confirmed Mbye had suffered an allergic reaction on Friday and was found outside his hotel room slumped on the floor.
"He stabilised and made a complete recovery," Hislop said in the statement.
"There is no risk with him playing or training, but he will need to have further tests done when he returns to Sydney.
"Moses developed a serious allergic reaction and he was worried enough to call me straight away.
"By the time I was able to see him, he was beginning to show signs of the reaction with a skin rash and swelling. I started treatment immediately and he responded quickly.
"His vital signs were observed for a number of hours after the event.
"He stabilised and made a complete recovery. We've got a well-stocked medical kit to deal with all sorts of emergencies."
Anaphylaxis is a severe medical emergency and the symptoms are potentially life-threatening.
Despite the scare, the 25-year-old was able to participate and complete the team's final training run on Saturday — clearing him to come off the bench against NSW.
Mbye said in a statement he feels ready to play.
"It was something that came on unexpectedly. I have never experienced anything like that before," Mbye said.
"It was obviously a reaction to something. I started feeling a bit itchy and light-headed — I phoned the doc and he managed it professionally. We had all our supplies here ready to go and we got on top of it early.
"I'm feeling sweet now and ready to play."
Queensland coach Kevin Walters didn't reveal the Mbye medical drama when asked about the utility at Saturday's captain's run.
Walters only spoke about giving Mbye more game time after the Tigers star had just seven minutes off the bench on Origin debutin Game 1.
"It depends on the situation of the game but we have a lot of confidence in what Moses can bring," Walters said.
"He had just a little window of opportunity in game one, we know he is a terrific player at club level.
"He showed that he could handle the step up in class albeit for a short period of time but he will be ready to go when we need him."
The NRL world was shocked by the breaking news on Saturday.
"It's really scary stuff when you hear that," NSW legend Michael Ennis said on Fox League.
"Often in Origin you hear about vomiting and diarrhoea and bugs and that sort of stuff. But this was serious stuff. Lucky the doctor was there right on queue to save Moses. He's a very lucky man."
Blues great Luke Lewis said on Saturday night: "It's so scary.
"I tell you who I do feel for, his family having no control (over the situation). It's just mind-blowing."
