Williams left the game after falling awkwardly and spraining his left ankle. Williams had X-rays, which were negative, but he didn't return to the game.
Williams left the arena on crutches and wearing a protective boot. He refused to talk to reporters after the game.
Utah coach Jerry Sloan would not comment on Williams' condition.
"That's not my position to speak on his condition," Sloan said. "I would never try to get a player back sooner than he should be ready to play. I would never jeopardize somebody's career."
Leading 68-64 early in the fourth quarter, the Jazz pulled away when Andrei Kirilenko's basket started an 8-1 run. Kirilenko scored six points in the spurt that put Utah up 76-65 with 7:07 left.
Kirilenko scored 18 points off the bench for the Jazz (3-3) and Paul Millsap added 14 points.
Williams pulled up for a 3-pointer midway through the opening period. He made contact with Chicago guard Derrick Rose when elevating for the shot and fell to the floor. Rose was called for a foul on the play.
Williams was carried off the court by two teammates as he grimaced in pain. He then left the floor for the locker room on a wheelchair.
Williams, who was on the gold medal-winning U.S. Olympic team at the Beijing Olympics, has career averages of 15.3 points, 8.1 assists and 2.9 rebounds while appearing in a total of 242 of a possible 246 career games, including all 82 during the 2007-08 regular season.
"Most important thing is be cautious. When he is ready to play, we will put him out there," Sloan said.
Rose, the No. 1 overall pick, started and scored 11 points in 40 minutes. Tyrus Thomas, who fouled out in the fourth quarter, led the Bulls (1-4) with 15 points and 14 rebounds. Larry Hughes scored 10 points.
Chicago played without guard Ben Gordon, who was out with a jammed right toe.
The Bulls beat the Jazz on Friday night in a game played on the University of Illinois campus in Champaign.
"I thought we played quite better last night. We didn't shoot the ball well tonight and we didn't move the ball well tonight either," said Luol Deng, who finished with six points for Chicago in 25 minutes.