NSW fullback Jarryd Hayne has revealed he felt "awful" throughout the side's series-clinching 6-4 in Origin II after battling a serious stomach bug for 24 hours.

After the match Hayne said had never gone into a game feeling more worried after a stomach bug caused vomiting and diarrhoea that kept him up most of the night before the game – but said he was never a chance of not taking the field.

"I didn't really have a fever, it was more just the bug going through my system," he said.

"I had nothing in me then the doctor came up to me about 10 o'clock [last night] and said I could eat til the next morning. I spewed my dinner up, I [lost] my lunch out – I was starving, I got up about 7:30 this morning, had a massive breakfast then kind of felt sick again."

He said after a plain lunch of boiled rice and chicken he felt sick again then "just pretty much felt awful the whole game", in which he was kept relatively quiet by a Queensland side that had clearly done its homework on the Origin I game breaker.

However he said some unsympathetic words from a friend got him focused on the task at hand.

"It was actually good, a saw a friend in the foyer, I bumped into him today, he kinda looked me straight in the eye, he had no sympathy for me, he goes 'everyone's been there'," Hayne said.

"He rattled off a couple of great American players [who had been through similar things and taken the field], he pretty much just looked at me going 'don't make any excuse'.

"That really changed my mindset and stopped me feeling sorry for myself. It was tough but no-one's going to care about that on the footy field."