Grant, the Dally M rookie of the year, will make his Origin debut in Wednesday's decider against NSW at Suncorp Stadium.

It will cap a stellar year in which Grant turned a loan stint at Wests Tigers into a breakout campaign.

"The progression that he's had over the last few years, it hasn't been a surprise to me or the Storm because we've seen it first-hand playing in the Queensland Cup," Smith said.

"He's been one of the best players in that competition the last two seasons."

The comparisons between Grant and Smith are inevitable, with many viewing the central Queensland product as the obvious successor to the 37-year-old in the Storm's No.9 jersey.

It took Storm coach Craig Bellamy however to make Grant realise how lucky he was to be a young hooker at a club with the game's most capped player.

"Harry obviously was playing Queensland Cup and we could see that he had something about him but after the (2018) season we had a review and I said 'how often do you sit down with Cameron and talk about being a dummy half?'," Bellamy said.

"He sort of looked sideways and said 'I don't'. I said, 'you've got the best-ever dummy half here, probably the best-ever player that's played the game in your position and you don't talk to him about things that happen on the field and where you can improve and what his ideas are?'

"The next year, every time I come to my office him and Harry were sitting in front of a computer, so I probably didn't help Smithy too much there."

Smith though says as good as Grant has been in 2020, he's confident there's more to come from his protege to come for the Storm and the Maroons.

"I still see a fair bit of improvement which, for me, I expect out of a young player," Smith said.

"Harry's got a lot of parts in his game he can work on and build throughout his career."

Australian Associated Press