Manly star Tom Trbojevic is facing a a 10-week recovery due to his torn pectoral muscle, which will rule him out of the Australian sides for the World Nines and Tests against New Zealand and Tonga.

Sea Eagles club doctor Ameer Ibrahim said Trbojevic would suffer no long-term effects from the surgery on his left upper arm. His absence from this year's NRL finals series is a massive blow for Des Hasler's team.

After being a part of the NSW Origin team's series win, he would have been a walk-up starter in coach Mal Meninga's Kangaroos team for the Nines and for the Kiwis on October 25 and Tonga on November 2.

"At the earliest it will take 10 weeks for him to get better after the operation, which is scheduled for later this week," Ibrahim told NRL.com.

Trbojevic's pectoral tendon was pulled off the humerus, or arm bone, when he lunged to try to tackle Storm winger Josh Addo-Carr. 

"They drill a hole through the humerus and then they will anchor the tendon into the bone through a tunnel," he said.

"It will be as strong as the original."

Dr Ibrahim said he spoke with Trbojevic on Saturday night in the Lottoland sheds, explaining to him the likely necessity for surgery.

The club put out a statement on Sunday saying the pectoral tear had "a likely rehab of three to four weeks". He explained the discrepancy in the two recovery scenarios as being the extreme in options facing the 22-year-old fullback.

"It was more that at this stage of the season you have to look at all options. And one option was leaving it alone in the short term so Tom could return given the grand final was in five weeks time," he said.

"That option was weighed up because there'd been a precedent before of that happening with Michael Gordon in 2017. After discussing with the surgeon today  he [surgeon] elected the best course of action was to operate early rather than wait."

As for Trbojevic's future for Manly in 2020, NSW and Australia, there would be no stopping him.

"Absolutely he can return to playing football at this level. There will be no long-term effect from this."

Fifth-placed Manly are assured of a finals berth and could finish fourth if they beat Parramatta on Friday and the Rabbitohs lose to the Roosters on Thursday, however the Sea Eagles could drop to sixth if they lose to the Eels.

Trbojevic's older brother Jake also tore his pectoral muscle in the first game for Australia during the 2017 World Cup.

"It's disappointing to lose him [Tom] at this stage. When I did it there was surgery and three months out."

Tom has managed just 12 games for Manly this year, with two earlier hamstring strains. Manly won 10 of those matches.

It begs the question of whether Manly can survive long in the NRL finals without him. The Sea Eagles are fifth with one round remaining and could realistically finish anywhere between fourth and sixth.

"There's a lot of perceptions out there in rugby league," Sea Eagles prop Martin Taupau said on Monday.

"Look, we're the only ones who can turn it around this week against Parramatta," he said of Friday's round 25 game at Bankwest Stadium.

"That's our focus and our talking point, not Tom. We've lost Thommo [forward Joel Thompson] out for the year with a broken arm.

"But it's only the 17 players in the group that can turn things around. We've got a lot of energy and confidence we can do that."

Jake knows his younger brother has plenty of football ahead of him.

"He's pretty frustrated. It's been one of those years for him really. When he's been on the field he's been outstanding for us but he can't seem to string too many games together – it's tough," he said.

"I guess he'll learn from it – and he's only young with a lot of footy ahead of him. So hopefully there's a lot more opportunities for him to play finals footy.

"As a club, we haven't played too much finals footy recently so he was all excited for that."