Jake Trbojevic's Rugby League World Cup is over after just one game due to a torn pectoral muscle but the Kangaroos lock is still hopeful of being fit to start the NRL season for Manly.

Trbojevic boarded a flight back to Sydney on Saturday, with the Sea Eagles star unsure if he will require surgery after scans confirmed the debilitating injury.

The 23-year-old ended Friday night's tournament opener in hospital after he was injured trying to tackle England's James Graham late in Australia's 18-4 win.

"It felt pretty weird just the way it happened," a disappointed Trbojevic admitted.

"I didn't' think too much at the time but it definitely didn't feel right and when I did the test I had no strength.

"I'm going to go back and talk to the Manly medical staff ... It might require surgery, we're not too sure at the moment but hopefully it's right for next year."

The prognosis should be positive.

Pectoral injuries usually require a three-month lay-off, leaving Trbojevic free to return to Manly a month before their opening-round clash with Newcastle on March 9.

It will come as a relief for the Sea Eagles, who will already be without representative centre Dylan Walker for the start of the season due to shoulder and leg injuries.

But the injury could leave an Australian team already missing a number of stars, carrying a squad of just 23 for the remainder of the tournament.

Under World Cup rules, countries can apply for a replacement player but it's understood exemptions are likely to be given only if injuries leave a team short in a particular position.

"Jake has been a fantastic representative of the Kangaroos and this is obviously disappointing for him," Kangaroos coach Mal Meninga said.

"He has been a selfless member of the squad and I am sure we will see him back in the green and gold soon."

Meanwhile, Jake's brother Tom is likely to be one of four debutants in Australia's side to take on France in Canberra next Friday.

Meninga has hinted he'll include the 21-year-old in his 17 for the clash with the European minnows along with fellow rookies Cameron Munster, Felise Kaufusi and Reagan Campbell-Gillard.

Ben Hunt, Josh Mansour and James Maloney are the other members of the 24-man squad who were not selected to play against the old enemy on Friday.

However Hunt is a certain scratching against the French anyway as he attends his wedding, while Mansour could also be unavailable pending the birth of his first child.

"I think the seven (players) will play next week. I'll talk to Cameron (Smith) about what he wants to do. We'll see what happens in the course of 5-6 days," Meninga said.