Billy Slater all-but declared himself a certain starter for Origin II in Sydney on Sunday, claiming his hamstring felt great after completing what he thought was Queensland's sharpest training session of the series on Wednesday.

And Maroons prop Dylan Napa completed all bar the final five minutes of the opposed session. A decision on his fitness is likely to be made on Thursday morning after his troublesome ankle has had time to recover from the session.

Slater claimed he was "really happy" with the progress of his injury and "I wouldn't be in this situation if I didn't think I was going to be right for Sunday".

Slater also revealed he was happy to vacate his position of fullback and switch somewhere else if it meant giving newcomer Kalyn Ponga the best opportunity to make an impact on the match.

Slater reflects on a great Origin career

However, he hinted the protégé who idolised him as a teenager is more likely to play a role in the middle of the field in the mould of Daly Cherry Evans, Cooper Cronk early in his career and Michael Morgan in past series.

"I think Kalyn is probably going to play multiple positions, and fullback could possibly be one of them; I'm not too sure," Slater said.

"I'm happy to play anywhere for the team, whatever is best for Queensland and our team. Anyone is willing to move around from their specific positions and bend a bit for the team.

"We haven't discussed that as yet but I'm sure Kevvie has a plan in his head.

"He's certainly going to be a great attribute to us coming onto the field when the Blues are a little bit tired and he's coming off the bench.

"He's a dangerous player, he's not a small lad, and he could play a number of positions and even handle the middle of the field.

"We've had Daly Cherry Evans and Cooper Cronk fill that role in the past; Michael Morgan has played that utility role of the bench too. I'm sure Kalyn could hold his own in the middle of the field."

There has been much speculation on how Maroons coach Kevin Walters fits Ponga into his attack.

It would be highly unlikely Slater would not play the whole game at fullback and, if there are no injuries, the best fit seems to have Ponga come into the game not long before half-time and rove around the middle of the ruck, targeting the Blues' tiring big men.

Blues wary of Ponga

Slater said his hamstring felt better after Wednesday's 90-minute session than before it, and he felt lack of five weeks' match time won't inhibit him.

"It's not ideal but that's the cards I've been dealt," he said.

"You understand what it takes to play a game and Origin. I am pretty confident I will be right for Sunday.

"It is still improving and I am really happy where it is. I'm giving myself plenty of time to overcome it, so I was happy how I got though the session.

"It's not your typical injury where you can feel the pain all the time.

"It's something you can manage and go through the process and steps, you can't just jump in and do all the rehab you want. It's a balance between rest and letting it heal and getting the strength and rehab into it."