Williams, 27, has had some back issues in the past.
He missed one game in 2006-07 with back spasms. He missed 16 games in the 2008-09 season with a lower back injury. On Dec. 29, 2010, he landed on his back after attempting to block a shot and did not play again until Jan. 26, 2011, missing 11 games over that time.
And in June 2011, Williams had "minor surgery on his lower back to alleviate the pain from a bulging disk," according to an ESPN report, and spent about two months that summer in recovery.
If Williams' injury is serious, it could have a significant impact on the Jazz as they play through the final month of the season. After Friday night's loss, the Jazz are now 0-12 in games he has missed this season.
Speed kills, as the maxim goes.
For a young big man in the NBA, it can be especially troublesome, says Clippers coach Doc Rivers, which is why he preached patience to former Jazz big man Al Jefferson when the two were together in Boston.
"You throw the ball into a big and he goes right away. Guys are cutting. Guys knock the ball out of their hand. They get deflections," he said. "I remember having Al Jefferson. … We used to count out loud. We used to make him literally hold the ball for four seconds before he could do anything with it. We would count, 'One, two, three …' He thought it was awful. But I think it taught him patience. Just wait. Let things clear."