Breanna Stewart was diagnosed with a bone bruise in her right knee, confirmed New York Liberty coach Sandy Brondello on Wednesday.
There is no timetable for Stewart's return.
"We want to be smart with it ... so when she's ready. But keep it fresh for the playoffs. I know she'll be back before then. How early she gets back before the end of the [regular] season, I don't know," said Brondello.
Stewart suffered the injury on Saturday night, with an MRI confirming that she escaped a major injury.
Stewart is averaging 18.3 points and 6.5 rebounds this season.