The Socceroos will be up against the might of Spain and Holland, as well as Contrera's native Chile, in Brazil next year and the former Monaco, Celta Vigo, PAOK and Olympiakos centre-back feels the form of New York Red Bulls star Cahill could be key.
"I don't know Australia's game too well. I am aware of their difficulties," said Contreras of the Socceroos who are now managed by former Victory head coach Ange Postecoglou.
"They work on their physical strengths and they will improve a lot with the new coach. Ange Postecoglou works a lot at the teams he coaches and surely he'll try to gain an advantage by using the wings with the view to finish off with the great forward Tim Cahill they have."
Contreras, who was a part of Chile's 2010 World Cup squad, most recently played for La Roja in a 2014 qualifier against Ecuador in October last year.
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