Paris Saint-Germain and Brazil striker Neymar left Tuesday's training session after just 15 minutes, the Spanish media reported on Tuesday.
According to the Spanish newspaper Marca, the striker left the session accompanied by the team's physiotherapist after suffering a pain in his ankle.
On Sunday, Brazil drew 1-1 with Switzerland, with Neymar playing the whole match for the first time having been sidelined for almost three months with a foot injury, which required surgery. The 26-year-old started to limp in the first half but said after the game he was not injured.
The Brazilian Football Confederation confirmed via its official Twitter feed that Neymar had pain in his ankle due to the numerous fouls he had suffered during Sunday's match.
"Neymar complained of ankle pains, due to the number of fouls he suffered [in the match] against Switzerland... He saw the physio and will receive treatment today and tomorrow morning, and will resume training tomorrow afternoon," team doctor Rodrigo Lasmar was quoted as saying by the confederation.
Brazil will play Costa Rica on Friday and Serbia on 27 June in their remaining two Group E fixtures.