England's hat-trick hero Lee Smith is battling to shake off a foot injury ahead of next Sunday's World Cup showdown with Australia.
The 22-year-old Leeds winger, who scored three of England's five tries in their opening 32-22 win over Papua New Guinea, reported the problem during the team's recovery session at their hotel on the outskirts of Townsville, just before they set off for Melbourne to prepare for their next game.
Smith is the only casualty from the match but an England spokesman said it was too early to say if he is doubtful for the game at the Telstra Dome. "He has undergone treatment and the injury will be assessed throughout the week," he said.
Meanwhile, England captain Jamie Peacock has promised his side would strive for a vast improvement on their unconvincing opening performance as they prepare to take on the defending champions.
England's unconvincing victory virtually ensures they will qualify for the semi-finals regardless of the outcome of their remaining group matches against the Kangaroos and New Zealand.
But they flew out of Townsville on Sunday to set up a base in Melbourne knowing that the hard work has only just begun.
"The World Cup is not won in the first game," said Peacock, who was one of England's best performers on Saturday. "It would be upsetting if you put your greatest performance in in the first game.
"We know there are areas where we need to vastly improve and I think we're used to that in Super League, improving on your performance from the week before.
"If we are to go further in this competition, we are going to have to improve defensively and respect the ball a bit more.
"It's all right playing but, if you make an error, you have to go out and defend it and I don't think we did that well enough. We played dumb."