The bizarre departure of Rachal from the team moved Chris Spencer to left guard for the Bears' Week 12 game against Minnesota. Spencer was injured during the game, which brought Williams to left guard.
And Williams, deactivated for the Bears' first 10 games this season, will start at left guard in Week 13 against Seattle.
Williams served those 10 games as another set of eyes for the Bears (8-3) offensive line, wrote the Chicago Sun-Times. He started in the Bears' final seven games of the 2011 season, and signed a two-year extension late last season, worth $1.89 million.
He signed with Chicago as an undrafted free agent in 2009 and looks to make an impact as the Bears host the Seahawks. If the playoffs ended after Week 12, the Bears would be hosting the Seahawks in the Wild Card round of the NFC Playoffs.
Chicago leads Green Bay by one game in the NFC North, while Seattle owns the conference record tiebreaker over Tampa Bay for the last seed of the playoffs.