The 23-year-old Real Madrid star “underwent imaging exams that confirmed an injury to his posterior left thigh muscle,” the Brazilian Football Confederation (CBF) said Friday in a statement.

It said Vinicius, a key piece of Brazil’s attacking arsenal, had been ruled out of next week’s match against arch-rivals and 2022 World Cup champions Argentina in Rio de Janeiro.

Vinicius had earlier said the outlook was not good for him to be fit to face Argentina.

“Based on what the doctors have told me, it will be a bit difficult,” he 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.

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.

Brazil take on Argentina, who top the qualification standings, on Tuesday in Rio’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.