Newcastle Knights halfback Mitchell Pearce out for 10 weeks

Newcastle's fears have been confirmed with Mitchell Pearce to undergo surgery this week on his left pectoral muscle which will rule him out for 10 weeks.

The star NRL halfback went for scans on Monday afternoon revealing a tear that requires immediate surgery.

It comes as the Knights struggle to name a 21-man squad in the face of a crippling injury toll that worsened in a 22-13 loss to St George Illawarra on Sunday.

Fullback Kalyn Ponga is set to make his return from offseason shoulder surgery against the Gold Coast on Saturday but the Knights will be strapped for bodies and will need to apply for dispensation to name players from outside their top 30.

The NRL club's injured list reached crisis levels on Sunday with the Knights also lost fullback Tex Hoy (hamstring), David Klemmer (knee) and Kurt Mann (concussion).

Mann appears set to miss the clash with the Titans on the Gold Coast after he was knocked out attempting to make a tackle in the second half Sunday's loss to the Dragons.

Scans ruled out serious injury for Klemmer but he remains in doubt to play against the Titans with a six-day turnaround.

The Knights' wounded list already includes Bradman Best (elbow), Lachlan Fitzgibbon (shoulder), Edrick Lee (hand) and Phoenix Crossland, all unavailable this week.

"I don't think I'll be able to name 21," coach Adam O'Brien said after the game on Monday.

"We lost Dom (Young, knee) in reserve grade today.

"Naming the team is probably going to be a really big hurdle this week."

Forward Jacob Saitifi is also facing a two-week stint on the sidelines for a grade one shoulder charge on Mikaele Ravalawa in the 56th minute of Sunday's loss.

However, if he accepts the early guilty plea he will miss just the Titans match, adding to the rapidly shrinking list of available players.

O'Brien expects Queensland star Ponga will be back, revealing he was close to taking the field on Sunday but was asked to get an extra week of contact work in as he recovers from off-season shoulder surgery.

"He'll get a whole block of contact this week, he'll get a little bit more because he hasn't played tonight," O'Brien said on Sunday, although he's disappointed Ponga won't be joining a fit team.

"That was the real thing we were looking forward to was getting guys like Bradman, Ponga, Blake (Green) in there with (Pearce) and Brails and all of them.

"We've just got to stick together and work really hard on our rehab for the injured guys and get the team back on the park

"If we keep that character about us we'll be thereabouts at the end of the year when we put that team back out there."