But coach Josh Hannay is urging patience with the 20-year-old, who will become the third player in as many weeks to make his NRL debut as a starting halfback.
In the Titans' system since he was 15, Harrison replaces Lachlan Ilias as No.7 following the dismal round-nine loss to Canberra.
But the Tweed Heads product, who completed his first NRL pre-season while still in high school, has been in the frame since well before then.
"I could've easily been comfortable giving him an opportunity sooner," Hannay said ahead of Friday's game in Gosford.
"This decision to play him isn't a reactive one based on the performance last week."
Harrison joined the Titans' top-30 roster this season and has impressed Hannay with his decision-making and physical toughness.
"You don't want to throw these young men into deep waters if you don't think they can swim. I wouldn't have done that if I didn't think he was capable of standing up to the challenge," Hannay said.
"I just hope that everyone's respectful of the fact that he's a young kid on debut playing in a key position. He's highly touted, he's going to have a long career in this game, but it's his first game of NRL."
Harrison's debut comes after fellow young guns Kade Reed and Joey Walsh played their own first NRL games at halfback for St George Illawarra and Manly, respectively, in rounds eight and nine.
Both men were subject to heavy media and fan interest before, during and after their debuts and Hannay is aware there will be similar scrutiny on Harrison.
The playmaker has already made waves during a distinguished schoolboy career that peaked with captaining Palm Beach Currumbin to victory in the 2024 National Schoolboy Cup.
"This game has a history of putting a lot of expectation on the next big thing, if you want to call them that," Hannay said.
"There will be external pressure, but I do feel like it's my job and our job to make him understand that there's no internal pressure.
"He doesn't need to see this game as a one-and-done type of situation where he needs to go out and show it all in one game. He'll be up here with us now for a little while."
An extended run in the first-grade team is likely to spell a longer axing for new recruit Ilias, who has now been dropped by South Sydney, St George Illawarra and the Titans in as many seasons.
Ilias has already approached Hannay for clarity as to how he can become a week-in, week-out first-grade halfback.
"We'll just continue to work with Lachie, he's been wonderful for us," Hannay said.
"He's really held his gloves up all year, we had a really good discussion about why I've made this decision during the week. (He) handled it like an absolute pro. He was really happy for Zane."