Tim Duncan sprained his left knee and right ankle in the first half of the San Antonio Spurs' 96-86 victory over the Washington Wizards on Saturday night.
Tony Parker scored 19 points, Danny Green added 15 and Tiago Splitter had 12 for San Antonio (38-11), which has won 18 straight at home.
John Wall scored 21 points and Martell Webster had 14 for Washington (11-35), which has lost 13 straight to San Antonio.
Webster rolled into the back of Duncan's legs while fighting for a rebound with 3:54 left in the second quarter, and there were audible gasps in the crowd while the All-Star was on the floor holding his left knee for several minutes.
The severity of the injuries is not known, but Duncan did not return to the bench after being helped off the court by teammates Stephen Jackson and DeJuan Blair.
Duncan, who was listed as probable, returned to the lineup after missing the past four games with a sore left knee. Recently selected to his 14th All-Star game, Duncan is averaging 17.5 points and 9.8 rebounds per game this season.
He had eight points and five rebounds in 13 minutes before the injuries, helping San Antonio get off to a fast start against Washington.
The Spurs used their ball movement and rotating defense to dominate the Wizards from the start.
Green ran in front of Wall to grab the opening tip, sprinting to the basket to throw down a one-handed dunk against the former No. 1 overall pick. San Antonio opened the game with a 15-4 run sparked by Parker and Duncan. The Spurs' All-Stars were a combined 5 for 5 from the field with Parker picking up three assists in the spurt.
Washington shot 35 percent from the field in first quarter and finished at 40 percent overall.