He was helped off the field early in the second half of Australias 62-0 trouncing of the United States Tomahawks in Wrexham.
Initial reports suggest he has a posterior ligament problem in his left knee. The Kangaroos have already lost second rower Luke Lewis.
The Australians skipped to a 38-0 halftime lead with Brett Morris bagging four tries in the first 40 minutes while Jarryd Hayne scored three in the second half and also finished with four on the day.
For the Tomahawks it was a tough if anticipated end to an exceptional RLWC debut appearance. There was much for them to cherish, though, after starting the event as 500-1 long shots to reach the quarter-finals.
In next weeks doubleheader semi-finals at Wembley Stadium in London, the Australians will meet the winner of the all-Pacific quarter-final between Toa Samoa and Fiji being played at Halliwell Jones Stadium in Warrington early tomorrow (live on SKY Sport 2, 4.00am kick-off NZT).
In todays second quarter-final England conceded a shock early try to France but recovered to post six unanswered tries in a 34-6 win at DW Stadium in Wigan.
England fullback Sam Tomkins collected the man of the match award in his final outing at his home ground before joining the Vodafone Warriors. However, he finished the match ignominiously, sent to the sin bin for the final few minutes for a professional foul.
Englands second half effort was several notches down on the first 40 minutes with just one try in 37 minutes before adding a final touchdown in the 77th minute.
England will now play the world champion Kiwis in the first semi-final at Wembley Stadium next Sunday morning (2.00am kick-off on SKY Sport 2 NZT). Australia's semi-final against Toa Samoa or Fiji kicks off at 4.30am NZT.
At Glyndwr University Racecourse Stadium, Wrexham
Kangaroos 62 (Brett Morris 4, Jarryd Hayne 4, Greg Inglis 2, Cameron Smith, Cooper Cronk tries; Johnathan Thurston 7 conversions).
United States Tomahawks 0.
Halftime: 38-0 Kangaroos.
Referee: Henry Perenara (New Zealand).
Kangaroos: Billy Slater; Brett Morris, Jarryd Hayne, Greg Inglis, Darius Boyd; Johnathan Thurston, Cooper Cronk; Matt Scott, Cameron Smith (c), James Tamou; Greg Bird, Sam Thaiday; Paul Gallen. Interchange: Daly Cherry-Evans, Josh Papalii, Andrew Fifita, Corey Parker.
United States: Kristian Freed; Bureta Faraimo, Taylor Welch, Michael Garvey, Matt Petersen; Joseph Paulo, Craig Priestly; Mark Offerdahl, Joel Luani, Eddy Pettybourne; Clint Newton, Matt Shipway; Danny Howard. Interchange: Tui Samoa, Roman Hifo, Mark Cantoni, Les Soloai.
At DW Stadium, Wigan
England 34 (Josh Charnley 2, Ryan Hall 2, Sean OLoughlin, Brett Ferres tries; Kevin Sinfield 5 conversions).
France 6 (Vincent Duport try; Thomas Bosc conversion).
Halftime: 22-6 England.
Referee: Ashley Klein (Australia).
England: Sam Tomkins; Josh Charnley, Kallum Watkins, Leroy Cudjoe, Ryan Hall; Rangi Chase, Kevin Sinfield (c); James Graham, Michael McIlorum, Chris Hill; Sam Burgess, Ben Westwood; Sean O'Loughlin. Interchange: James Roby, George Burgess, Brett Ferres, Liam Farrell.
France: Morgan Escare; Damien Cardace, Jean-Philippe Baile, Vincent Duport, Clint Greenshields; Thomas Bosc, Wiliam Barthau; Jamal Fakir, Kane Bentley, Remi Casty; Olivier Elima (c), Sebastien Raguin; Gregory Mounis. Interchange: Eloi Pelissier, Younes Khattabi, Antoni Maria, Mickael Simon.