NSW back-rower Greg Bird will have scans on his injured ankle on Monday afternoon, with fears he could join Jarryd Hayne in being a spectator for the State of Origin decider.

Hayne arrived in camp on Monday morning declaring he needed a miracle to prove his fitness by running at full pace by Wednesday, but he wasn't given a chance to test his injured hamstring - ruled out by doctor Nathan Gibbs at the team medical.

He will be replaced in the side by Newcastle winger James McManus, who is due to arrive in camp on Monday afternoon, but that may not be the end of the drama for the Blues.

Bird said he was giving himself 'a fighting chance' of being fit, but he looked long odds as he limped into the Blues camp with a moon boot on his left ankle.

The rugged back-rower suffered the injury playing for Gold Coast against Penrith in Darwin on Saturday night.

He said it occurred in the opening minutes of the encounter, but he was able to play on until the hour mark.

After an initial assessment by Gibbs, Bird was sent for an MRI, with James Tamou to also have scans on a pectoral injury.

Skipper Paul Gallen was also wearing a moon boot as he arrived into camp, though he appeared in far less discomfort than Bird with the foot injury he sustained in Origin II.

Should Bird be ruled out, Sydney Roosters forward Boyd Cordner will make his Origin debut in the decider.

'I don't really know what to feel at the moment, it still hasn't sunk in,' Cordner told AAP.

'I'm happy and excited, just looking forward to the week ahead.'

Hayne, NSW's most experienced player, revealed the frustration he was feeling with an injury which occurred when he turned out for Parramatta 48 hours after starring for the Blues in Origin I.

He admitted later that the fatigue of backing up had played a role in the injury.

'When I first did it we were looking at two weeks, then it went from three to four and here I am now,' Hayne said prior to being ruled out.

'It's been a roller coaster. It's probably been the worst injury I've had, the extent and not knowing how long I'd be on the sidelines for.'

Asked what it would mean to miss the decider, Hayne said: 'Just being a part of it knowing that I've based the pre-season around this game, I've based this whole season around this series - everyone has.

'For that to be taken away through injury is obviously devastating.

'There's nothing I can do. Whatever I could do I've done.'