Lucas Paquetá will undergo intensive treatment on a hamstring injury in the hope of playing for Brazil at the World Cup again.
The Flamengo midfielder limped off the pitch at half-time of Brazil's 2-1 win over Japan on Monday.
"Paquetá underwent an imaging exam that confirmed a muscle injury in the back of his left thigh," Brazil's Football Confederation (CBF) said in a statement.
"The player will follow an intensive treatment protocol, under the supervision of the Brazilian national team's medical staff, with the goal of recovering and returning to action as soon as possible."
Paquetá has been ruled out for Brazil's round of 16 encounter against Norway in New Jersey on Sunday and it remains to be seen if he will feature again for Brazil at this tournament.
Sources have told ESPN that Paquetá has a Grade II strain, which would likely see him sidelined for three weeks.
The former West Ham star, who has started in all four of Brazil's games in the tournament, remains hopeful.
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"Faith...I've been through this before," Paquetá, 28, wrote on Instagram.
Brazil are also missing Raphinha, who injured his hamstring in Brazil's 3-0 win over Haiti in the group stage. Bournemouth winger Rayan has since been playing in his place.
