According to Stephen Czarda of the team's official website, Williams' knee injury "will soon require surgery."
"This is uncharted water for me," Williams said, per Czarda. "I've never had a surgery in my life, not like a real surgery. I had a staph infection in high school where they just had to cut it out, but I've never had to get anything repaired. Never broke a bone."
Williams missed a grand total of one game between 2012-2014, but he doubled that mark during the 2015 campaign when he dealt with head, back and knee ailments.
The six-time Pro Bowler proceeded to sit out four games a year ago after he was slapped with a four-game ban for violating the NFL's substance-abuse policy.
When he's been active, Williams has continued to perform at an elite level as one of the NFL's premier blindside bodyguards.
Now on the shelf for the final two games of the regular season, Williams will likely be replaced by Ty Nsekhe, just as he was during last season's suspension.