Vidal's recovery time hinges on how the operation goes, though the situation does not look good, according to a source on the medical team treating him in Barcelona.
A key member of Chile coach Jorge Sampaoli's team, Vidal has suffered a tear to the external meniscus of his right knee. He aggravated the problem playing for Juventus, crowned Serie A champions at the weekend, in the second leg of their Europa League semi-final against Benfica last Thursday.
Chile were pinning their hopes on the versatile and energetic 26-year-old midfielder in a tough group at the tournament in Brazil starting on June 12 and his absence would be a major blow to the Andean team.
The Chileans face world champions Spain, the Netherlands and Australia in Group B.