Brazil were left to count the cost of Saturday's World Cup last-16 victory over victory as Neymar suffered a thigh knock and midfielder Luis Gustavo picked up a second yellow card.
"We need to evaluate it but we should have three, four or five days to try and make sure he can play the next game," said Brazil coach Luiz Felipe Scolari of Neymar, who took a heavy knock to the thigh after a crunching challenge from Charles Aranguiz with the match just four minutes old.
"I don't understand how you can do that and not be booked," added Scolari of a challenge that left Neymar requiring treatment.
Neymar at least managed to complete the game and avoid receiving a yellow card that would have ruled him out of next Friday's quarter-final against Colombia.
However, Brazil will have to do without another key player in that match after midfielder Luiz Gustavo was booked for the second time in the competition.
The Wolfsburg player has been one of the hosts' best performers so far and Scolari may now be forced to recall the under-fire Paulinho, who was dropped from the starting line-up against Chile.