The 20-year-old halfback moved from the Sydney Roosters to join brother-in-law Matt Lodge at Red Hill after playing one game at the elite level.

He's had to wait for his chance, but Kodi Nikorima's switch to the New Zealand Warriors and his teenage replacement Tom Dearden's ankle injury has suddenly thrust him into the spotlight.

O'Sullivan will partner Anthony Milford in the halves against Parramatta at Sydney's Bankwest Stadium on Saturday, just a short drive from his junior club Glenmore.

Dearden is facing up to eight weeks on the sideline, but coach Anthony Seibold is confident O'Sullivan can fill the void.

"He's been really consistent particularly for the past four or five games for (Queensland Cup side) Norths," Seibold said.

"I've spoken to (Norths coach) Rohan Smith and he agrees with me that O'Sullivan is in a better position to take his opportunity now than probably five or six weeks ago.

"It's probably been a bit frustrating for him because he came to the club for an opportunity ... it's his time in the jersey now and we're looking forward to seeing what he can do."

Returning Queensland gun Matt Gillett will be in his ear on the same flank and Seibold said his time logged on the training park so far should mean there isn't the "clunkiness" that crept in following Dearden's injury last weekend.

"I don't think there will be (problems with combinations)," he said.

"He (O'Sullivan) has been at the club even before I arrived and he did a whole heap of reps with the NRL team over the pre-season.

"He's got a really good understanding of footy. He's a smart young fella. We don't see any concerns there."

Seibold also said hooker Jake Turpin would retain his spot in the starting side ahead of fit-again Andrew McCullough in a reward for his form since the long-time No.9's absence through injury.

Australian Associated Press