Fitzgibbon is the only major selection casualty from the embarrassing 44-point defeat although bench utility Jack Johns also lost his place in the 17-man squad to meet the Sydney Roosters on Friday night with forwards Daniel Saifiti and Jesse Sue both returning from injury.

Dom Young is believed to have retained his wing spot by the skin of his teeth with O'Brien sticking with the giant 19-year-old despite two costly early errors against Melbourne that set the tone for the game.

Centre Kurt Mann was another who would have also come under the microscope after an unhappy night in both attack and defence against the Storm after coming out of Queensland Origin camp last week.

In a major blow to Newcastle's chances of upsetting the fifth-placed Roosters, veteran halfback Mitchell Pearce and teenage centre Bradman Best were left out of the squad.

O'Brien has opted to err on the side of caution with both players, who have now been given an extra week to fully recover from their injuries.

Pearce is out with a minor hamstring tear that sidelined him for the Storm game while Best hasn't played for the last five weeks following ankle surgery.

O'Brien is hopeful both will be right to take on the Canberra Raiders on Saturday week.

There is also still a cloud over prop David Klemmer after he was concussed early in the first half against the Storm and did not return after failing a HIA.

Klemmer was named on the bench but still has to pass a series of concussion protocols and be cleared by a specialist before being allowed to play against the Roosters with a short turnaround not helping his cause.

READ MORE:

Toohey's News - Knights centre snubbed

Saifitis sign new Knights deals

LISTEN:

Mark 'Ogre' O'Meley podcast

Fellow prop Jacob Saifiti also picked up a minor ankle injury but is expected to recover in time.

The decision to dump Fitzgibbon is a clear sign of O'Brien sending a message to his mis-firing players about the standards required if the Knights are to play finals footy again this season.

The 27-year-old backrower has been a regular starter in the side over the past five years after debuting in the top grade back in 2015 and is among the club's highest paid players.

O'Brien would not be drawn on his reasons for axing Fitzgibbon but it's believed to be around his effort areas in defence.

"Lachie and I have had a number of conversations and he fully understands the areas of his game he needs to really concentrate on and work harder at," O'Brien told the Newcastle Herald.

"I think the message is out there loud and clear that our performance against Melbourne was unacceptable and a long way short of what we should accept and expect.

"I'll be very disappointed if we don't get a positive response from everyone against the Roosters."

Experienced backrower Tyson Frizell admitted the performance against Melbourne had dampened the mood among the players in camp on the Sunshine Coast.

"It's not too enjoyable the day after a game like that but I guess you just have to get on with it," he said.

"We are all together and it's a time for us to nut out what we did wrong and where we can get better. If we want to do something in this competition and get towards the finals at the back end of the year, we need to move on quickly."

Frizell admitted time is running out for the side to turn things around.

"We know that which is why we are now so focused on this week," he said. "What's happened has happened and we've got another strong team this week so we are preparing as well as we can. It's been a different kind of preparation up here but every team is in the same boat so there are no excuses for us."

The Knights go into the game with an awful record against the Roosters, having only beaten them once in the past 10 meetings between the teams.

IN THE NEWS:

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: