Knights prop Daniel Saifiti.

A pre-game pact between Newcastle's forwards to replicate David Klemmer's trademark aggression sparked Daniel Saifiti's battle royale with the Burgess brothers.

Saifiti was in everything throughout the Knights' 20-12 defeat of the Rabbitohs, not least a wild brawl just before halftime that led to the young forward, teammate Lachlan Fitzgibbon and Burgess brothers Sam and Tom sin-binned, and the latter accused of headbutting Saifiti.

Burgess may yet have to answer to the match review committee after replays showed the English prop leading his head into Saifiti's.

The Knights prop had no hard feelings over the incident, even if he did think Burgess headbutted him, and even if he didn't know which twin he had cleared the air with after full-time.

"I thought he did, but I think it's just a natural thing," Saifiti said of Burgess's alleged headbutt.

"But it is what it is things happen, you move on to next week.

"They [Tom and George] look exactly the same, I shook hands with one of them after the game and said, 'good game, good luck for next week'.

"Even on the field we were challenging each other, nothing got personal, it was just rugby league. Big aggressive forwards going at it."

The Knights will have to go at it for the next four to six weeks without Klemmer as the Blues star has been sidelined with a broken wrist suffered in Origin I on Wednesday.

Saifiti more than stood up in the big man's absence, matching it with the Burgess twins and Souths captain Sam after he and his fellow Newcastle forwards vowed to not let Klemmer's absence snap what is now a six-game winning streak.

"Me and Jimmy [Gavet], Herman [Ese Ese] and Sione [Mata'utia] were talking about it before the game." Saifiti said.

"We just said we've all been playing good when Klem's been there, we just need to step it up an extra gear. We felt like we didn't have to do anything extraordinary, we just thought 'step it up'.

"He obviously makes 200 metres a game and is good in defence. It's not just one person, not just me by myself to pick up the slack.

"Jimmy told me he's got my back, I told him I had his. I thought we did well without him but at the same time Klem's our forward leader and I can't wait for him to come back."