Maroons assistant Josh Hannay said on Sunday morning Napa was still not 100 per cent fit but he would nurse his injured ankle through a match Queensland must win to keep the series alive.

"It is hard to place a percentage on the injury but he has done everything asked of him this week - he is ready to go," he said.

Hannay disagreed that the NSW forwards outmuscled Queensland in game one in Melbourne but believed Napa would help the Maroons pack respond to the series-opening loss.

"I don't think they (NSW pack) were as dominant as what has been said in the media," Hannay said.

"I thought we held our gloves up and held our own at certain stages. It's about maintaining that dominance for longer periods tonight.

"(But) there were periods where our middle was disappointed with the way they handled it.

"The threat NSW poses is their speed and their little men through the middle. We just need our middles to handle that."

Hannay said veteran fullback Billy Slater was primed to make an impact in his landmark 30th Origin match after missing game one through injury.

"We did a little presentation for Billy last night just to acknowledge this is his 30th - he is one of the greatest to ever wear the Maroons jersey," Hannay said.

"He's highly motivated to go out there tonight and do his job for Queensland.

"He will put in a big performance. The key is that the other 16 back him up."

Hannay claimed there was no pressure on brilliant 20-year-old bench utility Kalyn Ponga, who will make his keenly-awaited Origin debut for Queensland.

"There's no pressure at all. He is coming into an environment he will own for the next 10 to 15 years," Hannay said.

"This is the start of his Origin journey. We have all the confidence in the world that when he is injected he will make a real difference."

Hannay admitted the Maroons were nervous as they tried to extend their stunning run of 11 series wins in 12 years in their first season without retired greats Cameron Smith, Cooper Cronk and Johnathan Thurston.

"Yeah but NSW would be nervous too," Hannay said of rookie coach Brad Fittler's Blues.

"There is a lot on the line, two new football sides trying to make their mark on State of Origin.

"We know what is in front of us. It will be a tough task but our preparation has been faultless and that gives us great confidence coming into tonight."

Australian Associated Press