Neymar will undergo surgery after rupturing the anterior cruciate ligament and meniscus in his left knee while playing for Brazil.
The attacker, 31, was carried from the pitch on a stretcher during Tuesday’s 2-0 defeat to Uruguay.
He fell during a run in the 44th minute at the Centenario Stadium and was immediately surrounded by players from both teams as he held his left knee.
“The striker will undergo a surgical procedure, on a date yet to be defined, to correct the injuries.
“The Brazilian national team’s medical department, under the supervision of Dr Rodrigo Lasmar and Al-Hilal, are in permanent contact and aligned in the player’s recovery.”
Responding to criticism of that performance, he said: “I don’t come here on vacation, much less to go for a walk. I came to do what I love most, which is to play football and defend my country.
“Obviously, we are there doing our best, giving our best, and often the result doesn’t come.”
Brazil will now be without their star man for next month’s World Cup qualifiers with Colombia and Argentina — and beyond.