Bulls coach Tom Thibodeau was unsure of the prognosis for Watson, who was using crutches to get around at the United Center before the game.
"I don't know yet," Thibodeau said. "[Athletic trainer] Fred [Tedeschi] will have a better deal after [Tuesday]. So we'll see where it is."
Watson suffered the injury late in the second quarter of Sunday's win over the Philadelphia 76ers, but remained in the game and scored seven of his nine points in the fourth quarter.
Thibodeau was confident that the Bulls would be able to compensate for Watson's absence, saying John Lucas III would step in for Watson.
"We've been there before," Thibodeau said. "The thing about our team that we like is our depth. One guy goes down, the next guy steps up, he's got to be ready to go. John's played extremely well all year for us. He's the next guy up."
Watson is averaging 9.8 points and 3.9 assists for the Bulls this season.
Nick Friedell covers the Bulls for ESPNChicago.com and ESPN 1000.