The Spurs said in a statement that the 21-year-old was injured during the team's game against the Golden State Warriors on Friday.
"The San Antonio Spurs today announced that Victor Wembanyama underwent an MRI that revealed he has a left calf strain," the Spurs said in a statement.
"The injury occurred in Friday night's game against the Golden State Warriors. The team will provide updates as appropriate."
Although no timetable for Wembanyama's return was given, reports say that the towering center would miss a "few weeks."
Wembanyama had been listed as questionable to play in San Antonio's win over the Sacramento Kings on Sunday and ultimately played no part in the fixture.
Spurs coach Mitch Johnson said the team were erring on the side of caution in their handling of Wembanyama's calf problem.
"Obviously, we've seen around this league recently, the calf-tightness thing is not something you want to take lightly," Johnson said. "Don't want to push it there."
Former No.1 Draft pick Wembanyama has made a dazzling start to the season, averaging 26.2 points and 12.9 rebounds in 12 games.
Wembanyama returned to the court after a lengthy layoff last season caused by deep vein thrombosis in his right shoulder.