New Manchester United midfielder Fred did not train with Brazil on Friday as he continues his recovery from an ankle injury, sources have told ESPN FC.
Brazil are now based at Tottenham's training base prior to flying out to Russian Federation, and footage posted to Twitter by Luiz Felipe Castro showed Fred go to ground after a challenge from Real Madrid's Casemiro.
The club announced that they had reached a deal to sign the Brazilian midfielder earlier this week, although stopped short of announcing him officially as a United.
"Today Fred had trauma in his ankle but it is too early to say anything about it", Lasmar said.
Brazil players have praised the intense training sessions but critics say Tite's hard-line approach could affect the future of his players in the World Cup.
He hopes Fred's injury is nothing serious and that he will be back amongst the squad sooner rather than later.
"Everyone wants to fight for a position, our trainings are very strong, " left-back Marcelo said.
After their group opener against the Swiss, Brazil take on Costa Rica in St Petersburg before travelling to Russian capital Moscow to face Serbia.