Vinicius Jr may miss World Cup qualifier against Argentina with injury
"Based on what the doctors have told me, it will be a bit difficult," the 23-year-old said after Brazil went down 2-1 in Barranquilla on Thursday.
Vinicius left the field in the 27th minute of the World Cup qualifier against Colombia, with his side leading 1-0.
"I think it's the same injury as before. I felt a pain at the back of my thigh," he said, before adding that tests would be carried out on Friday.
The Brazilian star missed a month of action after he injured his right thigh at the end of August in a league match for Real Madrid.
He missed Brazil's first two South American qualifying matches against Bolivia and Peru in September.
Contacted by the AFP, the Brazilian Football Confederation (CBF) did not provide information on Vinicius' fitness.
Brazil take on Argentina, who top the qualification standings, on Tuesday in Rio de Janeiro's Maracana Stadium.
The home side, in fifth place, are already without goalkeeper Ederson, defender Danilo, midfielder and captain Casemiro and star attacker Neymar, all through injury.
