But before the 21-year-old second-rower aims to make every post a winner to become a regular in the NRL, he wants to send his departing teammates off the best way possible in the NSW Cup.

Barnett has unfinished business to attend to with the Mounties when the NSW Cup minor premiers take on Newcastle in Sunday's preliminary final at Leichhardt Oval.

It's been a breakthrough year for Barnett, who got a taste of first grade with two impressive performances for the Raiders in round 22 and 23.

He was also named the player of the year in the NSW Cup earlier this week as a reward for his outstanding season for the Mounties.

Barnett doesn't want this season to end just yet, but he's itching to build on his strong showing for the Raiders next year.

"Everyone is talking about the end of the season to put their heels up, and I'm thinking I can't wait to get back into pre-season to try and prove myself in the NRL," Barnett said.

"I just have to get through this season, hopefully we finish it well, and see where it takes me. I want to get into next year. I really want to prove myself to everyone and I want to try and get a first grade spot."

Barnett had to bide his time before being brought in for his debut in the round 22 clash against Wests Tigers.

He retained his place for the following week's game against Manly before being replaced by under-20s captain Luke Bateman for the last three games of the season.

"It didn't worry me at the time, I got that experience, which is more than I thought I would have got this year," Barnett said.

"Ricky [coach Ricky Stuart] spoke to me about bringing me up and taking me back down and just putting me up there for the experience. It made me hungry to play better and do well for the Mounties and get back up there."

If the Mounties lose against the Knights, it will be the final game for several Raiders-contracted players.

Second-rower Joel Edwards, halfback Mitch Cornish and forward Jeff Lynch are all leaving the club at the end of the year, while the future of hooker Glen Buttriss is uncertain.

While Barnett didn't want to look beyond next week, he said there was plenty of motivation to send those players off on a high.

"Those guys have been unreal for the Raiders and for the Mounties," he said. They're talented players. We want to play well for each other and see where it takes us."

In the other preliminary final, the Wyong Roos take on the Canterbury Bulldogs at Leichhardt Oval at 1pm.

NSW Cup preliminary final: Mounties v Newcastle Knights at Leichhardt Oval on Sunday, 3.10pm. TV: Live on Fox Sports 1.