The Madrid forward provided an assist for Gabriel Martinelli to put Brazil in front, before being substituted in the 27th minute in Barranquilla.
He was later seen with strapping on his left thigh.
Madrid are already without goalkeeper Kepa — who has a thigh injury — and Aurélien Tchouaméni, who has a broken bone in his left foot, as well as long-term absentees Thibaut Courtois and Éder Militão who both suffered ACL tears in August.
Jude Bellingham was also forced to withdraw from the England squad on Tuesday after injuring his shoulder during Madrid’s 5-1 win over Valencia.
Vinícius will now undergo tests to determine the extent of his injury.
Sources told ESPN that he was in less pain than when he suffered the hamstring problem in his right leg which kept him out for a month between August and September this season, but there was nonetheless concern about his prognosis.
“I think it’s the same injury as last time,” Vinícius said post-match. “I got a knock, and I felt it [again] later. I’ll have tests, to see what it is.
“From what the doctors say, it will be difficult [to play Argentina on Wednesday] but we’ll try everything.”
Vinícius has shown his best form of the season in recent games, scoring twice in Madrid’s 5-1 win over Valencia last Saturday.
Camavinga returned to Madrid for evaluation on Thursday and was set to undergo a scan to assess his knee injury, and how long he will be unavailable.
An initial diagnosis suggested he could be out of action until January, sources said.
Madrid are second in LaLiga with 13 games played, two points behind surprise leaders Girona, and top of Champions League group C with four wins out of four.