But after learning under the wing of Cooper Cronk, he has not only learned to love the unfamiliar position, he's being sized up for a possible State of Origin debut in the NSW halfback jumper.

For much of his career, the two-time NRL premiership winner has been considered an instinctive, ball-running five-eighth.

But through a mix of circumstance and personal growth, he's proven he's likely to spend much of the second half of his career at halfback.

Cronk's decision to play with a broken shoulder blade in last year's grand final forced Keary to take ownership of the side and he responded by winning the Clive Churchill Medal.

And in the Sydney Roosters' past two outings, Keary has been shifted to halfback because of Cronk's hamstring injury, starring in wins over Manly and Parramatta.

"If you told me 12 months ago that I was going to have to do it, I wouldn't have been too happy," Keary said.

"But if I have to do it today, I think I know what I'm doing. I know how to get the job done.

"It's hard to explain to people. I feel sorry for some young halves - I'm lucky I've got Cooper to speak to about it. He's been doing it for 15 years which helps me a lot."

Keary said he had picked up the finer points of playing halfback "subconsciously" from observing Cronk.

Cronk is a chance to return on Thursday night against Brisbane and trained on Sunday with the side.

Keary was expected to come into Origin contention this year and NSW coach Brad Fittler said he was considering him as either a No.6 or No.7.

"It's cool to be talked about," Keary said.

"I don't hear it too much. It can only be a good thing if people are talking about you for rep stuff."

At a time when Keary is playing the best football of his career, incumbent Blues halves Nathan Cleary and James Maloney have looked well below their best in a struggling Penrith side in the opening three weeks.

And Fittler said he would consider Keary this year for both the No.6 and No.7 jumpers.

"H's a brilliant halfback. The touch and the kicking under pressure, that is a job that has taken years and years of practice," Fittler told the Sunday Footy Show.

"Spending that time with Cooper last year and nailing it in the grand final and doing whatever's needed at the moment.

"He can play both positions; that's where he's going to put pressure on all of them (Maloney and Cleary)."

Australian Associated Press