The injury-hit Knights are in for their toughest test this season at McDonald Jones Stadium on Sunday against a high-flying Melbourne outfit.

The second-placed Storm are coming off a club-record 70-10 win over the Warriors, while Newcastle have fallen to 14^th following their fifth consecutive defeat - a 39-2 loss to Parramatta that players have labelled "embarrassing" and O'Brien felt compelled to apologise for.

The trying task of bouncing back against the Storm has been made all the more difficult after outside backs Dane Gagai and Hymel Hunt both suffered cheekbone fractures at the weekend.

Hunt, who is yet to feature in the NRL this season, was injured playing NSW Cup and requires surgery. He had only just returned from a pre-season knee injury and now looks set to miss a further six weeks. Gagai is expected to be back in a month.

Brodie Jones also hyper-extended an elbow but has been named to play. He is yet train this week but is expected to be given until Sunday to prove his fitness.

"He has settled quite well, I was quite concerned after the game," O'Brien said of how Jones pulled up.

"We don't play until Sunday, so he is every chance of playing."

Should Jones be ruled out, the only other noted back-rower in the 24-man match squad is Jack Johns, who has played only one reserve-grade game following off-season shoulder surgery.

Prop Pasami Saulo is the only other forward in the squad to have played NRL.

The club's list of sidelined first-grade players will extend to nine if Jones fails to take to the field with Jayden Brailey, Lachlan Fitzigbbon, Mitch Barnett, Dom Young, Jirah Momoisea and Mat Croker also unavailable.

The situation has left no room for O'Brien to drop players over recent weeks following poor showings.

The Knights have signed play-making utility Anthony Milford, but he can't play until round 11 and only with further NRL approval.

The tally of injuries is also tracking similar to the club's past two seasons.

After seven rounds, O'Brien has used 24 players - mirroring the amount used last year and one more than in 2020 at the same point in the season.

The coach said it was hard to say if the injuries encountered so far this season had been more challenging to manage than in his first two years in charge, in each of which the club lost multiple players for extended periods.

"It's hard to put a handle on which season is tougher, when you're going through injury tolls that is tough," he said.

"But Gags' cheekbone and Hymel's cheekbone, they're contact, trauma injuries. They're not over-training, they're not load or mismanaged.

"They're all trauma-based injuries and hopefully our luck changes."

Five Knights players missed eight or more games across the club's 25-match season last year, including halfback Mitchell Pearce (13), Kalyn Ponga (10), Lachlan Fitzgibbon (15), Bradman Best (8) and Edrick Lee (entire season). Blake Green also retired after round 11.

In the shortened 2020 season, key outs across the 21 matches the Knights played included: Jayden Brailey (missed 19), Connor Watson (16), Tim Glasby (14), Bradman Best, Edrick Lee and Andrew McCullough (10), Mitch Barnett (8), Daniel Saifiti (7) and Blake Green (6).

"It's an annual event, but thankfully we've clawed our way out annually as well," an optimistic O'Brien said.

"I'm hoping for that but I am expecting us, regardless of personnel, to put in a better performance.

"I know we can fight our way out of it. We've done this in the past; we've lost four or five games straight and we've managed to get a couple of guys back and inject some energy."

The Knights are expected to have to deal with their injury and suspension situation for at least another two weeks, but from round 10 onward should get a steady trickle of players back.

Mitch Barnett will be able to play in the round-10 game against the Bulldogs in Brisbane, while the club's head of medical Craig Catterick has also slated Jirah Momoisea, Lachlan Fitzgibbon and Mat Croker to be available too.

Catterick said Dom Young (round 11), Dane Gagai (round 11-12) and Hymel Hunt (round 14) would follow, while Brailey's return is yet to be determined.