Croker was injured during Newcastle's 18-16 loss to Newtown in Saturday's NSW Cup match at Leichhardt Oval but soldiered on, and it was not until after the game that a fracture was confirmed by X-rays.

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He underwent surgery on Sunday night and is expected to face at least six weeks on the sidelines.

Kurri Kurri product Sattler was immortalised when his jaw was shattered early in the 1970 grand final, yet he stayed on the field to skipper South Sydney to a famous victory over Manly.

In more recent times, Shaun Kenny-Dowall helped Sydney Roosters win the 2013 grand final after suffering a hairline fracture of his jaw, while a year later South Sydney's Sam Burgess defied a smashed cheekbone to win the Clive Churchill Medal with a heroic performance in the title decider against Canterbury.

Newcastle's physical-performance manager Hayden Knowles said that while 22-year-old Croker was obviously disappointed to be missing games, his attitude towards the setback had been "outstanding".

"He's such a good kid," Knowles told the Newcastle Herald.

"The first thing he did was he messaged me to say he was going to use this time out to get himself fitter. He just approaches things really positively.

"Some blokes would be down in the dumps, but he just wants to get back and train.

"That's just way he is. I love working with him, because he's one of those real effort players.

"And all the boys respect him for that reason too."

The timing could hardly be worse for Croker, who has played in four NRL games, including a standout display in the round-two win at home against Wests Tigers.

With first-choice forwards David Klemmer, Mitch Barnett, Lachlan Fitzgibbon and possibly Tyson Frizell all unavailable, the Taree Panthers junior - who won Newcastle's players' player award in NSW Cup last season - was under consideration for a recall to the top squad for Thursday's clash with Manly at McDonald Jones Stadium.

Meanwhile, Knowles said Frizell was still a chance of playing against the Sea Eagles, despite suffering a hamstring strain in last week's 18-0 loss to Cronulla.

The Test and Origin back-rower remains confident of proving his fitness.

"It was a very, very minute strain," Knowles said.

"It wasn't a typical hamstring injury, where you do it running. He just felt it while he was twisting in a tackle and thought it was a cramp.

"So it's only a tiny strain and we'll give him every chance.

"He's certainly fighting with the physios and staff and saying he wants to play this week, so I expect he'll be named to play.

"If he does miss a week, that's all it would be."

Meanwhile, speculation is mounting that the Knights will soon announce a contract extension for skipper Kalyn Ponga.

Ponga reportedly met for lunch with Dolphins coach Wayne Bennett in Sydney on Saturday.

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