Williams will serve as the Rams' lead back for Sunday's game against the 49ers, a source told Jeremy Fowler of ESPN.com.
The Rams will make Cam Akers inactive for the contest and could look into trading him away after he managed just 29 yards on 22 carries while playing 33 percent of the offensive snaps in Los Angeles' season-opening win over Seattle. Williams, who worked behind Akers in Week 1 but played 67 percent of snaps and finished with 15 carries for 52 yards and two touchdowns while also drawing two targets, should now get a chance to build on that performance. Though the matchup with a stingy San Francisco defense isn't an ideal one for fantasy purposes, Williams' season-long outlook should see a big boost if Akers remains out of the backfield mix in the weeks to come.