"I recommend Vidal return to competition two months after the operation, three months would be even better," Cougat told the daily El Mercurio, according to Xinhua.
The Juventus player was operated on his right knee a month ago in Barcelona.
"Making him play before that would be to rush him," said Cougat. "It is risky to do so, because the knee meniscus can tear again."
Vidal, who is set to travel to Brazil with the rest of the team Thursday, is due to play in at least one of the three first round games of the tournament, according to coach Jorge Sampaoli's plans.
"We know the World Cup is important. It's every four years. But sometimes an injury can leave you out of competition," said Cougat.
"It's not up to me to bar him from playing, but the how, when and where Vidal will be able to play again is a consensus decision that should include the player, the coach and the medical team."
The Chilean national team plays its first match June 13 against fellow Group B member Australia at the Verdao Stadium in Cuiaba.
Its second match will be against Spain June 18 at the Maracana Stadium in Rio de Janeiro, and its final first round match will be against Holland June 23 at the Sao Paulo Arena.