'Would be a huge loss': Queensland star in major doubt for State of Origin decider

Queensland fear they could lose their most experienced player, Matt Gillett, to injury for Wednesday's rugby league State of Origin series decider.

It took two days, but the Maroons revealed on Sunday that 20-Origin game backrower Gillett was in doubt after suffering groin soreness during Friday's training session.

Teenager David Fifita is set to come off the bench and be injected into the starting second-row with 18th man Ethan Lowe earning an Origin debut at ANZ Stadium if Gillett is ruled out.

"He (Gillett) would be a huge loss if he doesn't play," said Maroons hooker Ben Hunt.

"He's played the most games in our squad. He's a huge presence in our team, we would definitely miss him."

Queensland doctor Matt Hislop said Gillett had undergone scans and was receiving treatment, missing Sunday's opposed training session.

"We will continue to provide treatment and assess his progress to give him every opportunity to play," Hislop said.

Fellow Maroons back-rower Felise Kaufusi was backing Gillett to play on Wednesday.

"There's a long way to go to game day," said Kaufusi. "I have some confidence he can be right for it.

"I have seen him walking around. We will give him all the time that he needs to get ready."

But Kaufusi was confident two-game Origin youngster Fifita would step up if Gillett withdrew.

Asked if 19-year-old Fifita was capable of playing big minutes if he started, Kaufusi said: "If he is asked I am sure he could and would be willing to".

Hunt also backed South Sydney forward Lowe to impress off the Maroons bench if handed an Origin debut.

"He's playing good footy at Souths. If he is playing I don't think he will let us down," he said.

Reporters initially thought Gillett had aggravated the broken nose he suffered ahead of Queensland's 38-6 game two loss in Perth when he left the trianing field early on Friday.