Rodrigo Lasmar said tests conducted on his right ankle showed that Neymar has a ligament injury and will not be fit to play against Switzerland on Monday. Danilo has suffered similar damage to his left ankle.
“Neymar and Danilo went through a MRI on Friday afternoon and we found ligament damage in the ankle of both of them,” he told reporters.
“They will miss the next game for sure and we will be cautious as they will undergo treatment in order to try to get them in shape so they can play again in the World Cup.”
He added: "It's important to remain calm, an evaluation will be conducted daily so we can have more information and take the most appropriate decisions," Lasmar said, adding that "the goal is to have him recover" in time to still play in the tournament.
Neymar was receiving treatment at the team's hotel Friday after getting injured in the 2-0 win against Serbia in Brazil's opener.
The Paris Saint-Germain striker sprained his ankle in the second half of a bruising match against Serbia on Thursday. He was in tears while sitting on the bench with ice around his ankle and limped off the field on his way to the locker room.
Additional reporting by Reuters.