Australia fly-half Stephen Larkham is hopeful of playing again at the World Cup despite undergoing a second operation on his knee on Monday.
Larkham first went under the knife last week
Larkham, 33, was aiming to play against Canada on Saturday after recovering from his first operation last week.
But he had arthroscopic surgery after his knee became infected and he is out of Australia's quarter-final against either England or Tonga on 6 October.
Larkham said: "I'd be very happy if I played in the semi-final a week later."
He first went under the knife just over a week ago after his knee locked up during kicking practice.
But he had to undergo further minor surgery after feeling pain while out for a run on Monday.
Larkham added: "I was limping quite badly and the doctor told me I had to go back in.
"They've cleaned it all out now and I'm pretty confident - I'll just take it easy for the rest of the week and hopefully get running by Monday, but reducing the swelling is the biggest thing right now."
He's very disappointed because he was coming along quite well
And the earliest he is now likely to return is in the semi-finals in Paris in mid-October if Australia reach that stage and the injury heals in time.
"I've spoken to the medical staff and they really can't say when he'll be fit to play," said Aussie coach John Connolly.
"We know we won't have him for the quarter-final but if all goes well he may be available the following week.
"He's very disappointed, obviously, because he was coming along quite well. He's one of our most experienced players and very much in our plans."
Connolly said that 21-year-old Berrick Barnes is "favourite to start at this stage".