Neymar was in tears when he carried off on a stretcher, before being taken to hospital in Fortaleza.
Coach Luiz Felipe Scolari said: "Neymar was going to be hunted. For three matches that has been happening."
Team doctor Rodrigo Lasmar told Brazil's SportTV: "Unfortunately, he's not going to be able to play. He is very, very sad."
"It's not serious in the sense that it doesn't need surgery, but he'll need to immobilise it to recover."