Marshall on Thursday said he could absolutely see the comparisons between Makasini and All Blacks star Jonah Lomu, but backed the 18-year-old to deal with the hype.
Makasini will play centre in the Tigers' season-opening clash against North Queensland at Leichhardt Oval on Saturday, after scoring on debut in the final round last year.
The Newington College product already looms as the biggest-name rookie to watch in 2026, and admitted this week returning to the 15-man code was a long-term option.
But Marshall insisted on Thursday that was not a concern for the joint-venture club, who are desperate to hold onto Makasini beyond the end of next year when his contract expires.
"I don't talk about recruiting publicly. But what I will say is Heamasi is really important to us," Marshall said.
"And we'll prioritise whatever we need to do to make sure he stays here.
"But rugby, for me, is not a concern at the moment. All I'm worried about is he's still got two more years here under contract that we need to get the best out of him."
Marshall said Makasini would be comfortable playing in the centres for the injured Starford To'a, after spending most of pre-season there.
Highly-touted by the Tigers, Makasini announced himself in the NRL by bumping off Dylan Edwards and two other Penrith defenders with the try of the pre-season.
That reignited comparisons to the legendary Lomu, who played his last Test five years before Makasini was born.
"If you look at the 1995 World Cup, the highlights look the same. That's why it's crazy," Marshall said.
"He's had some comparisons to some great players, but what I like is he doesn't let that affect his mindset and the way he is.
"But again, we've seen a couple of things in trials. It's not the same when you play an NRL game."
Now in his third year as a coach, Marshall was handed an extension through until 2030 amid the Wests Tigers' boardroom dramas late last year.
A tough persona has also been on show, with the club releasing footage this week of Marshall telling rookies in November where "the f***ing door" is if they don't meet standards as the Tigers bid to return to the finals for the first time since 2011.
"That's just who I am and being genuine in what I actually believe and think," Marshall said.
"It's how you adjust and react to that. And the reaction from the players was outstanding."