FIFA has told ESPN it will investigate the circumstances of the injury that has ruled Brazil forward Neymar out of the rest of the World Cup.
The Barcelona player sustained a fractured vertebra in Friday's quarterfinal defeat of Colombia, and had to be stretchered off following a collision with Juan Camilo Zuniga.
Referee Carlos Velasco Carballo has come under fire for his handling of a feisty game that witnessed 54 fouls, while some have expressed their anger at Zuniga's challenge.
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"We are awaiting the official match reports and we will gather, as well as analyse, all the necessary elements in order to evaluate the matter," a FIFA spokesperson said.
Neymar was forced to return to Brazil's training camp in Teresopolis in an ambulance following the Colombia game.
The 22-year-old flew back to Rio de Janeiro with the rest of his Brazil teammates on Friday but rode the rest of the way to the camp separately.
Brazil's team doctor Jose Luiz Runco has told ESPN that Neymar, who is being accompanied by father Neymar da Silva Sr, will undergo rest and medication, while wearing a brace, "for about 15 days."
Runco added: "[The injury] bothers him while sleeping because of the pain."
Meanwhile, Brazil captain Thiago Silva has defended Zuniga for his challenge on Neymar.
Zuniga apologised to the former Santos man after the final whistle, and Paris Saint-Germain defender Thiago Silva, who used to play for AC Milan, insists the Napoli player did not mean to harm his international teammate.
"Zuniga does not have any nastiness in him. I know him from Serie A," Silva told AS.
"What he did, I think, was rash. I still have not seen the pictures, but I know that in these circumstances it was difficult to get the ball off Neymar.
"He was dominating. I am a centre-back, and I know that in situations like this one should be looked at more thoroughly."