Rio de Janeiro, Brazil (BBN)-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.

Neymar sustained a fractured vertebra in Friday's quarter-final win over Colombia and had to be stretchered off following a collision with Juan Camilo Zuniga, reports ESPN.

Referee Carlos Velasco Carballo has come under fire for his handling of a feisty game that involved 54 fouls, while some have expressed their anger at Zuniga's challenge.

"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 team-mates 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 Neymar after the final whistle, and Silva insists the Napoli player did not mean to harm his international team-mate.

"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."

BBN/SS-06July14-2:00pm (BST)