D-day looms for Dylan Napa after the injured Queensland prop admitted he faced a conundrum in his fitness battle ahead of Sunday's must-win State of Origin game two in Sydney.

Melbourne's Tim Glasby is on standby for Napa, who must convince coach Kevin Walters he has overcome an ankle ligament complaint at the Maroons' Wednesday training session at their Gold Coast camp to play Origin II.

While Napa was quietly confident of proving his fitness, he was wary of aggravating the injury on Sunday and leaving the Maroons a man down in their crunch clash.

Napa admitted it would be tough to leave the Maroons camp but didn't dismiss the notion of stepping aside for Glasby ahead of Sunday's ANZ Stadium blockbuster.

"I am really hopeful of playing. It would be pretty tough to say no to an Origin match in Sydney but in saying that I have to put the team first," Napa said.

"If I say 'it is good' and break down then I am letting the team and state down - that's the last thing I want to do.

"If the best thing for the team is for me not to play and Tim Glasby or whoever comes in at 100 per cent then I will do that for the team.

"But tomorrow will be the big test."

Sydney Roosters enforcer Napa was injured in the tri-colours' NRL last round win over Penrith, aggravating an ankle ligament complaint that sidelined him for two games last year.

Napa said it had improved dramatically in the last 24 hours but he still hadn't been able to run yet.

He's had just 12 hours sleep in the last three days with around the clock icing, physio and compression on the troublesome ankle.

"I wouldn't be the first to play on an injured ankle and I probably won't be the last if I do play," Napa said.

"I just want to get down there and try and even up that series."

Maroons winger Valentine Holmes said the early signs were good with Napa.

"He's walking around without his moon boot on today so that's obviously a good sign," he said.

"It doesn't help that it is a seven day, not a usual 10 day camp, but I am sure he will be good."

Queensland's other injury concern, veteran fullback Billy Slater (hamstring), must also pass a test on Wednesday but has all but been cleared by Walters.

The Maroons mentor gave players a Wednesday fitness deadline after a nightmare lead-up to game one which NSW won 22-12 in Melbourne.

Injury concerns Ben Hunt, Dane Gagai and Josh McGuire had to be nursed through training while Slater pulled out of Origin I just days before kick-off.

Queensland must win this weekend to keep alive their run of 11 series victories in 12 years.

"We were in the same situation last year so it is not unfamiliar territory for us," Maroons back-rower Gavin Cooper said.

"And heading back to Suncorp for a decider is a pretty big carrot to dangle."

Australian Associated Press