The Socceroos could be set to receive a major boost for their World Cup opener against Chile on Friday, with Chilean star man Arturo Vidal seemingly unlikely to feature in the match.
Vidal underwent minor knee surgery to repair a damaged miniscus on May 7 after helping Juventus to seal the Serie A title.
The procedure was intended to allow the versatile, energetic striker to play without pain in Brazil.
However, his rehabilitation has not proceeded as quickly as expected.
The 27-year-old came on in the 77th minute of Chile's 2-0 friendly win over Northern Ireland on Thursday and the brief cameo appears to have done him no favours.
Inflammation prevented Vidal from any meaningful involvement in training on Monday, prompting reports he could also be in doubt for Chile's other Group B matches against Netherlands and Spain. If that proves to be the case, he could be cut from the squad altogether.
Jorge Sampaoli's men face the Socceroos at the Arena Pantanal in Cuiaba on Friday (Saturday morning AEST).
They have until 24 hours before the game to replace Vidal in the squad for the tournament.