Barnett was sent off for an elbow to the jaw of Penrith forward Chris Smith in Newcastle's 38-20 loss in Bathurst on Saturday and his case has been referred straight to the judiciary. It is not the first time he has been in hot water with the game's law enforcers, but his teammates and coaching staff love Barnett's aggressive playing style, which has twice earned him the Danny Buderus Medal as Newcastle's player of the year.

"These things happen in footy," Knights forward Tyson Frizell told the Newcastle Herald.

"It might have looked intentional, but I know for a fact that he's not the kind of person who would deliberately do something like that.

"I don't want Barney to change the person he is, or the way he plays. He's been great for us and I guess sometimes things can go wrong.

"That's the way it is in footy. It's obviously in the process and the judiciary will deal with it, but as a teammate and a friend, I wouldn't want Barney to change the way he is."

Frizell has played with and against Barnett and described him as a "tough competitor" and a "great asset" to the Knights.

"Hopefully we have him back on the paddock as soon as possible," Frizell said.

Frizell's comments were echoed by Knights prop Daniel Saifiti, who has played alongside Barnett since they were rookies in Newcastle's hapless 2016 squad.

"Barney plays the game a bit like Latrell [Mitchell], [Victor] Radley," Saifiti said.

"That's what they're good at. They might tread the line a fair bit but that's why they're good players.

"Do they have to change the way they play? I don't think so.

"They're aggressive players and it's just a matter of finding the balance. I'm sure when Barney gets back out there he'll keep playing the same way, because that's what makes him such a good player."

Saifiti described the collision with Smith, which left the Penrith forward concussed and unable to play any further part in the match, as "a one-off thing".

"I don't think he meant to hurt the bloke," he said. "I know Barney really well. He's a good mate of mine and he's got a heart of gold.

"It was one of those things he got wrong and he paid the price for it, and we paid the price for it.

"I'm confident he won't be doing anything like that again."

The Knights have employed prominent lawyer Nick Ghabar, who has represented more than 100 NRL players at judiciary hearings, to handle Barnett's defence tonight.

It is understood they will plead gulity but try to convince the panel that there were mitigating circumstances, in particular that Smith loomed as a decoy runner into Barnett's path while the Newcastle back-rower was travelling at high speed and had his eyes focused on the ball.

Barnett will almost certainly be suspended but the sanction will be less severe if the judiciary accepts his raised forearm was careless or reckless, rather than intentional. He is set to join Lachlan Fitzgibbon (knee surgery) on the sidelines.

Frizell also hurt his knee against the Panthers but is expected to be cleared to tackle Cronulla on Friday.

Brodie Jones missed the Penrith game with COVID and Knights coach Adam O'Brien admitted his squad was running low on back-rowers.

"If you could pinpoint a position in the team, it's definitely that, the back-row stocks," O'Brien said.

"Brodie will return and hopefully this fella [Frizell], he normally pulls up pretty good the next day.

"But yeah, the back-row stocks are probably where we're thin a little bit, but we'll wait and see what pops up."

O'Brien said skipper Kalyn Ponga, who has missed two games with a knee strain, was "extremely likely" to receive a clearance to take on the Sharks.

Saifiti, who played his first game of the season against Penrith after being sidelined with a fractured tibia, said he felt "a bit rusty" but would be better for the run.

"The lungs were going and I was probably a step behind everyone in line speed, and my contact probably wasn't as good, but I can build on that," he said.