After saying last week that he was not 100 percent healthy, Neymar was left out of Brazil's main team Thursday at its World Cup training camp.
The Paris Saint-Germain striker is still being hampered by a foot injury.
Before heading to London on Sunday, Neymar said he had not fully recovered after a week of training with the national team in Brazil. But he predicted that he would be better for the tournament in Russia, which begins on June 14.
Brazil will face Croatia in a friendly on Sunday in Liverpool. It is not clear if Neymar will start.
In Thursday's practice, Brazil coach Tite used Philippe Coutinho and Gabriel Jesus up front.
Thiago Silva was also put in the practice team, in the place of Marquinhos.
Earlier, the Brazilian soccer confederation said midfielder Renato Augusto injured his right knee and could miss the game against Croatia at Anfield.
The 30-year-old Augusto is likely to be rested for the rest of the week.
Brazil has been practicing at Tottenham's training center since Monday and will stay until June 8.
The team's last pre-World Cup friendly will be against Austria on June 10.