Brazil forward Neymar left training early on Tuesday after feeling pain in his right ankle and will spend the rest of the day undergoing physiotherapy, the Brazilian Football Confederation said.
"He was feeling pain thanks to the large number of fouls he suffered in the Switzerland game," a spokesman told reporters on Tuesday. "He complained of pain and so he went to physio and he will train normally tomorrow."
Neymar stopped training in Sochi after a few minutes, leaving his team mates to continue preparations for their second World Cup game against Costa Rica in St Petersburg on Friday.
Neymar was fouled 10 times in the first match against Switzerland which Brazil drew 1-1.
The Paris St Germain forward was subdued in the match and unrecognisable from the man who became the world's most expensive footballer when he left Barcelona last August to join the French champions.
Neymar was out all of March, April and May with a fractured right foot and sprained ankle after he was injured in a French league match in late February.
