Curry exited Wednesday's loss to the Houston Rockets midway through the first quarter. He appeared to be in some discomfort just minutes into the game.
After the Warriors' 115-108 defeat, coach Steve Kerr said Curry had told him the injury was not one he had experienced before.
"Concern is high," Kerr said, and an MRI scan revealed the tear.
Curry, 38, has been playing at an elite level this season, averaging 27.8 points per game with 3.7 rebounds and 3.9 assists.
He is shooting a career-high 45.7% from three-point range and was instrumental in an eight-game Warriors winning streak that ended on Wednesday.
The injury is another blow to a Golden State squad already without Jimmy Butler and Moses Moody - both recovering from knee injuries.
Curry, a four-time NBA champion and two-time Most Valuable Player, missed 39 games last season, 27 of them with a nagging knee injury.
Follow the NBA better than ever
The best basketball league in the world is back, and Flashscore is improving our coverage of the NBA with match previews based on key stats and facts ahead of each game!
