Neymar was in tears as he left the field with an apparent knee injury at the end of the first half of Brazil's World Cup qualifying match at Uruguay on Tuesday.
The 31-year-old striker tripped and fell as he jostled for possession with Nicolas de la Cruz just before half-time. His knee appeared to buckle under his weight as he fell to the ground at the Centenario Stadium and he was immediately surrounded by players from both teams as he held his left knee, screaming in agony and writhing on the floor.
Neymar was then carried off on a stretcher with both of his hands on his face, looking in visible pain.
He used crutches as he left the stadium. Brazil's doctor Rodrigo Lasmar told reporters it was too early to determine the severity of Neymar's injury.
'We did all the tests and we will repeat them tomorrow. Those 24 hours are key to see how his knee will respond, how swollen it will be, and what images will show,' Lasmar said. 'Let's wait for the exams with calmness, evaluate with calmness, and tell you once we have a diagnosis.'
Neymar, who plays for Al Hilal of the Saudi Pro League, was criticized by fans before the World Cup qualifier because of his subpar performance during Thursday's 1-1 draw between host Brazil and Venezuela.
He headed to Saudi Arabia in August on an astounding deal that will see him earn around $300m on a two-year contract.
But if his knee injury is as bad as it appears on first look, it could sideline him for most of the first year of his contract. Indeed, if scans reveal major ligament damage it could even see him in a race against time to be available for the Copa America next summer, which is held in the United States from June 20 until July 14.
The Saudi league runs in parallel with the European season, with the current 2023-24 season ending in May next year.
Brazil lost the game 2-0 on the night in Montevideo. Liverpool forward Darwin Nunez opened the scoring in the first half - two minutes before Neymar was hurt.
Nicolas de la Cruz made the victory safe for Uruguay in the second half, 13 minutes from time.
The defeat leaves Brazil third in the CONMEBOL standings and face Colombia and World Cup holders Argentina next month.
