The Juventus midfielder is a fitness doubt for Friday's Group B clash with Australia in Cuiaba, after undergoing an operation at the end of the Serie A season, though Chile aren't ruling him out of the group opener just yet.
Vidal played 15 minutes of Chile's 2-0 friendly victory over Northern Ireland on Thursday, but it remains unclear whether the 27-year-old will be involved against Ange Postecoglou's men.
However, Vidal has not been yet been ruled out by Chile, and team doctor Giovanni Carcuro has calmed fears over the speed of his recovery.
"Arturo Vidal's recovery process is on the right track," Carcuro said at a press conference.
"The 15 minutes Vidal played against Northern Ireland weren't more intense than his previous work.
"The knee inflammation is something usual in Vidal's recovery process. There wasn't a relapse.
"Arturo Vidal progressed within the periods we planned for his recovery."
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