Now the 24-year-old is coming to terms with having to do so, figuratively speaking, for the good of the team.

After playing 53 of his first 56 NRL games as a starting back-rower or lock, Barnett was named on the bench for Newcastle's season-opening 14-6 win against Cronulla last Friday.

Knights coach Nathan Brown used Barnett and Aidan Guerra - who last season were both regularly 80-minute players - to great effect against the Sharks.

After big men David Klemmer, James Gavet and Tim Glasby produced an opening onslaught, Barnett and Guerra provided fresh legs and defensive work rate throughout the middle stages of the game.

Barnett finished with 19 tackles and 109 metres in attack in 37 minutes on the field but was left feeling that he had much more to offer.

"I want to play 80 minutes, to be honest," he said.

"That's the person I am. I want to play as much footy as I can, week in, week out.

"But I want to win as well, and if Browny thinks the best thing for the squad is to have me coming off the bench, I'm happy to do that.

"But the goal is to work my way into the starting side."

Barnett said it was "very different" taking a seat on the sidelines when his teammates were preparing for kick-off, although he can understand the tactical logic.

Himself and Guerra are both accustomed to playing in the middle, while Sione Mata'utia and Lachlan Fitzgibbon are more suited to the role of edge back-rowers.

"I've hardly ever come off the bench, but it's a role I have to play for the team, and I want to do it really well," he said.

"But I'm someone who pumps myself up for a game, and coming off the bench, I guess I'll have to delay that until maybe the 20^th minute.

"My preparation is going to have to change a fair bit, I guess, but guys like Tim Glasby and Kurt Mann have played a lot off the bench in their careers, so I can lean on them for advice.

"But also I'm going to have to work it out for myself."

Mann agreed that playing off the bench, as opposed to starting, required an adjustment in mindset.

"I was a little bit like Mitch," he said.

"I liked to be starting, especially having played in the outside backs. It wasn't until last year that I really started coming off the bench and playing in the forwards.

"I guess you can only prepare yourself during the week as well as you can, and you have to be ready to come on at any time, because there might be an injury or whatever.

"In my case, I just try to relax and not think about it too much."

Friday's win against Cronulla was Barnett's first in six attempts, and he said it would provide a huge boost to Newcastle's self-belief.

"They're a tough side and they really hung in there, but it was just great to see the growth in our team," he said.

"We messed up in the trials but we learned from that and the little things that we got wrong, we fixed them up.

"We were definitely confident, heading into it, just because of all the hard work we've done in the pre-season and the new players we've got here in the squad.

"We're definitely going out there to butt heads with whoever we play, and we did that. For the most part, I thought we dominated them."

Newcastle's next challenge will be to knock over another team expected to feature prominently at the business end of the season, Penrith Panthers, who they tackle at McDonald Jones Stadium on Saturday.

"Penrith, I reckon they'll be playing deep into the semi-finals if all goes well for them," Barnett said.

"So we've got to back it up. It's only round one and we need to keep going, taking it week by week and hopefully keep notching up the wins.

"It's a a good start but there's a long way to go yet."