The Newcastle Knights enormous injury crisis is threatening to grow, with the revelation star centre Bradman Best is no guarantee to play this weekend.

The Knights, already missing Kalyn Ponga, Fletcher Sharpe and Dylan Lucas for the rest of the year, as well as Adam Elliott through to the final rounds of the campaign, are now likely to need to find a new centre to replace Best, who has had a mixed year as a result of injury.

Already missing a chance to feature in the State of Origin arena for the New South Wales Blues, Best who has struggled predominantly with his hamstring injuries, has managed just 13 games this year of the 18 Adam O'Brien's side have played.

The Newcastle Herald are now reporting Best is no guarantee to play this weekend when they clash with the Canberra Raiders in the nation's capital.

He was spotted at training on Wednesday wearing a knee brace, and didn't take part in the club's field session.

The Knights, per the report, still believe Best could play, and it's unclear the severity of his injury at this stage.

If the star centre is ruled out, then it's likely a straight swap would be made with one of the reserves. Both James Schiller and Kyle McCarthy are in the 22-man squad and could be called upon.

Newcastle, who sit 14th on the ladder and still have a bye to come, are not out of danger from the wooden spoon after falling short against the New Zealand Warriors in dramatic circumstances on Sunday afternoon at home.

It marked the club's fourth loss in their last five starts, with pressure continuing to build on head coach Adam O'Brien, who may be axed at the end of the year.

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Already it has been reported that Blake Green and Josh Hannay are the most likely coaches to take over from the besieged O'Brien, who has been unable to get his side firing in attack this year.

The Knights sit just two points ahead of the Gold Coast Titans in last place, although are on equal points with the South Sydney Rabbitohs and Parramatta Eels, but are ahead on for and against.

Their bye will help, but a tricky run to the end of the year won't with matches to be played against the Raiders, Panthers, Cowboys in Townsville, Broncos, Sharks and Eels.