But Miles reckons he wouldn't have it any other way.

Miles was still getting his head around the representative retirement of newly signed Sydney Roosters No.7 Cronk, who promptly pulled the pin after last weekend's Rugby League World Cup triumph for Australia.

Cronk followed the lead of Maroons halves partner Thurston who will concentrate on club duties with North Queensland in what is set to be his 17th and final NRL season next year.

Michael Morgan is expected to get first crack at halfback with Cameron Munster tipped for five-eighth after his strong game three debut in Queensland's 2-1 series win in 2017.

New St George Illawarra recruit Ben Hunt, Brisbane's Anthony Milford, Gold Coast youngster Ash Taylor and the Bulldogs' Moses Mbye are also expected to put their hands up in 2018.

Either way, Miles admitted there were some tough calls to be made on the selection table next year - not that he was complaining.

"It is going to be an enormous headache that is for sure, but one we are looking forward to," Miles told Former Origin Greats website.

"We know that injuries, suspension and form will make a lot of decisions for us.

"But even then we are still going to have this massive headache of having to fit so many good, experienced players into a 17-man squad.

"It is going to be a really tough job. But, really, it's a great problem to have, isn't it?"

It's not just the halves that will no doubt ensure some heated debate for selectors.

Veteran fullback Billy Slater has also hinted that he will draw the curtain on his representative career in 2018.

Selectors also need to slot the inspirational Greg Inglis (knee) back into their backline among Valentine Holmes, Wally Lewis Medallist Dane Gagai, Darius Boyd and possibly Slater.

Test prop Matt Scott (knee) will also return.

But Miles was confident about their depth after being forced to blood eight rookies this series in the wake of their record 28-4 Origin I loss in Brisbane this year.