JT's 2nd thoughts on rep league retirement

The looming departure of Corey Parker has led to Queensland playmaker Johnathan Thurston having second thoughts about his own State of Origin retirement.

Thurston admitted to rethinking when he should walk away from Origin after injury concern Nate Myles (knee) was a confirmed starter for the Maroons in Wednesday's Origin III dead rubber in Sydney.

Thurston, 33, appeared to confirm he would quit representative football after the 2017 World Cup earlier in this year's Origin series.

However, the imminent Origin retirement of veteran lock Parker has ensured mixed feelings for the Maroons talisman.

Parker will play his 19th and final Origin when Queensland attempt a rare series whitewash in game three at ANZ Stadium.

"It's a bit harder to deal with because it feels like (my own Origin career) is starting to come to an end," Thurston said.

"But in saying that I am in love with it like it is my first series.

"I will miss it. It's quite special."

Asked about walking away in 2017, Thurston said: "I am having second thoughts now.

"For me it is about making it to the World Cup and making a decision after that - we will wait and see."

The wait is over though for Myles, who will start in the front row in Sydney next week.

A Queensland spokesman said he would bump Josh McGuire to the bench, with debutant Gavin Cooper to wear the Maroons No.14 jersey.

"He has played 30 Origins in the toughest position - when Nate stands beside you, you know you are safe," Thurston said of Myles.

"That's the aura he brings."

Winger Dane Gagai (thigh) underwent sideline drills at Friday's training session but is already a confirmed starter, according to Queensland coach Kevin Walters.

Thurston will play his 36th straight Origin on Wednesday as Queensland look to seal their fifth series whitewash.

Age has not wearied Queensland - nine players on the wrong side of 30 will run out for the Maroons on Wednesday night following the selection of 30-year-old "rookie" Gavin Cooper.

Thurston admitted it would be important for the Maroons to have staggered retirements in order not to leave a "void".

Centre Justin Hodges retired in 2015 and Parker has called time in 2016.

Thurston wasn't sure who was next.

"It would be a void if players retired at the same time," Thurston said.

"But I am sure (coach) Kev (Walters) has a plan in place to limit the effect.

"The selectors and Kevvie would have learned from NSW years ago to have a succession plan in place."

Thurston said Queensland hoped to cap their series triumph with their first whitewash since 2010.

"I have only been part of one. It's not often we are 2-0 up," he said.

"We have a great opportunity to create something special."