Veteran Peru forward Jefferson Farfan is currently being patched up in hospital after being knocked unconscious in training.
Australia face Peru in their final group game on Wednesday morning (AEST) requiring a win and a favour from France against Denmark to reach the World Cup knockout stages.
Farfan, who plays his club football in Russia for Lokomotiv Moscow, came off badly after a clashing heads with a teammate during training at their base in Khimki on Saturday.
The 33 year-old is in a stable condition but still being closely monitored.
Farfan has been a mainstay of the Peruvian national side since his debut as an 18 year-old in 2003, racking up 25 goals from 84 caps.
He scored against New Zealand in the qualification play-off for the World Cup to help Los Incas to their first appearance at the finals since 1982.
Peru's chances of reaching the round of 16 have already been extinguished following back-to-back 1-0 defeats to Denmark and France.