Newcastle Knights coach Nathan Brown says that while Brock Lamb "wasn't quite at the races last week", he still has the backing of the team's leadership group.

Lamb started at five-eighth for the first time in 2018 in Newcastle's loss to the unbeaten St George Illawarra Dragons on Sunday, replacing the injured Connor Watson. The day wasn't a happy one for Watson and the Knights.

Heading into Saturday night's clash with the Brisbane Broncos at McDonald Jones Stadium, Brown is backing Lamb to improve.

"I think everyone would agree that Brock wasn't quite at the races last week," Brown said.

"Brock knows that he has to pick up his defence and that is quite clear for everyone to see. That is the challenge if you want to be a first-grade player in the halves.

"Whether you're a good defender or not so much a good defender, you're going to get plenty of traffic.

"At the end of the day, you make decisions whether you want to do it or not and that's the difference between being a first grader or not I suppose. But he has got it within him."

Playing alongside Mitchell Pearce is a highly sought-after position, with Jack Cogger and Danny Levi also snapping at his Lamb's heels during Watson's absence.

Knights forward Lachlan Fitzgibbon understands how hard Brock Lamb works to fine-tune his defence.

"We forwards also need to step up and lay the platform for Lamb to do his magic off the back of it," Fitzgibbon said.

"Hopefully this weekend we can lay the platform for Lamb and Junior [Mitchell Pearce] and come up with a win."

Brown is wary of a Broncos team coming off a loss to the Gold Coast Titans last weekend.

Brisbane fullback Darius Boyd is one Bronco certain to attract Brown's attention.

"In my opinion, Darius Boyd has been one of their better players in the past decade I think. It's not a fluke that he's played in three grand finals in three separate teams.

"And when he is on-song what an outstanding player he is. It'll only be an amount of time before they win their share of games."

One thing Brown is not concerned with, however, is the controversial refereeing crackdown.

The Newcastle mentor believes that it is something the game has let go for too long, and if teams are doing the right thing, they will not be punished.

"As a whole, I think they're now refereeing the game as it should have been refereed a fair while ago and we probably wouldn't have got to this stage.

"I don't have a real issue with it myself."