Now Max King is just 80 minutes from realising a grand final fairytale with Melbourne Storm.

King, the 22-year-old grandson of rugby league Hall of Fame winger Johnny King, has enjoyed a remarkable rise since his mid-season switch from Gold Coast Titans to Melbourne.

King played nine of Gold Coast's first 10 games this season before falling out of favour, and had no hesitation in accepting an offer to join the Storm before the June 30 transfer deadline.

He then waited almost two months to make his Melbourne debut, coincidentally in a 24-8 win against Gold Coast in round 23.

But injuries to Christian Welch (knee) and Albert Vete (shoulder) have allowed him to string together five consecutive games, including back-to-back finals.

On Saturday he will again come off the bench as the Storm try to qualify for a fourth consecutive grand final by beating defending premiers Sydney Roosters at the SCG.

"I am still pinching myself that I am here. It's crazy," King told AAP.

"I was in a bad spot at the Titans personally. I was low in confidence, stuck in reserve grade. Things just weren't going my way.

"It was hard because the Titans first-grade team was struggling and I couldn't even make that team.

"I was beating myself up a bit. But I left with no hard feelings. Besides, you could say it has worked out pretty well."

King left Maitland in 2016 to play in the Titans' National Youth Competition team and less than two years later made his NRL debut, at the age of 19.

He played in a further 37 top-grade games for Gold Coast before moving from the cellar dwellers to the minor premiers.

In 2017, he told the Maitland Mercury "in Newcastle I was struggling to make the SG Ball team" when the Titans approached him.

"I just wanted to be at the club where I saw I had the best opportunity," he said at the time.

"I didn't see that at the Knights. As much as I wanted to stay in the Hunter with family, the pathway there wasn't clear for me.

"The Titans rang me and said they wanted to sign me and it was just more of the fact they wanted me.

"I could tell that's where the pathway was for me ... the Titans gave me the opportunity in the 20s and last year it just sort of blew up for me. They re-signed me on a full-time first-grade deal. "Everything has happened so quick."

At 1.92 metres and 110 kilograms, King has been used sparingly by Storm coach Craig Bellamy, but his round-25 effort against North Queensland (47 minutes, 122 metres, 29 tackles and a try) cemented his spot as an interchange impact player.