Newcastle Knights coach Wayne Bennett has made two forced changes for Sunday's round nine game against the Penrith Panthers at Hunter Stadium.

With Korbin Sims (suspension) and Matt Hilder (concussion) unavailable, young forwards Joseph Tapine and Pat Vaivai are set to make their NRL debuts.

Tapine, who will become player 250 for the Club, joined the Knights in season 2013 after playing in New Zealand's Bartercard Cup as a 17-year-old.

The talented second-rower trained with the NRL squad over the pre-season before an injury set him back on the eve of the season. Tapine returned to play the last month and has contributed strongly in the Under 20s unbeaten run.

Injured forward and fellow Kiwi, Jeremy Smith, looks forward to seeing the just 20-year-old make his debut.

"Joe is a young strong lad, he has some size to him which will help our forward pack on Sunday," Smith says.

"He can carry the ball well and has a good offload and while he is quiet, he has some mongrel about him.

"He won't be taking a backward step out there, I am excited for him and look forward to seeing him play and experience first grade."

Asked if the veteran forward has helped with any words of advice, Smith said he will save that for Sunday.

"I will talk to him tomorrow before the game, and I will just remind him what he does well," he says.

Meanwhile for 22-year-old Vaivai, who is in his third season with the Club, he gets his opportunity after impressing in NSW Cup.

"It’s huge for Patty and I think it’s really deserved as well," teammate David Fa'alogo says about Vaivai, who will be player 251 for the Club.

"He has been playing well in the NSW Cup.

"He deserves his opportunity and he is excited and really looking forward to it, so good on him.

"He’ll add a bit of grunt because he has got a bit of size and we’ve just got to show him the way."

Gates open at 11.30am on Sunday at Hunter Stadium, with NYC kicking off at 11.45am before the main game at 2pm. A reminder the Knights will wear black armbands. Tickets available at the gate or to purchase online, CLICK HERE.