LOS ANGELES -- The Rams have placed running back Kyren Williams on injured reserve, the team announced Saturday.
Williams, who injured an ankle in Week 6 against the Arizona Cardinals, will miss at least four games. The second-year running back will be eligible to return in Week 12 against the Cardinals.
The Rams are also without backup running back Ronnie Rivers, who injured a knee in the same game. Los Angeles put Rivers on injured reserve earlier in the week.
In six games this season, Williams has 456 rushing yards on 97 carries and 105 receiving yards on 13 catches. He has seven total touchdowns (six rushing, one receiving).
Earlier this week, the Rams elevated running back Royce Freeman to the active roster and signed running back Darrell Henderson Jr., who was waived by the team last season, to the practice squad.
In addition, the Rams signed running back Myles Gaskin off the Minnesota Vikings' practice squad Wednesday and added him to their active roster. The Rams also have rookie sixth-round Zach Evans on the roster.
On Friday, Rams coach Sean McVay said he had a sense of what the running back rotation would be Sunday against the Pittsburgh Steelers but declined to share. He did say Henderson would be active, saying the running back has "done a great job of being able to quickly reacclimate himself back to a lot of the things that we've done."
"There's a possibility we'd have all four guys up, and then if not, then we'll go with three," McVay said. "And we're really still working through, truthfully, who those three would be between those four guys, and we might have all four of them up."