The Rams rode the strength of their defensive line to a fast start.
So with uncertainty surrounding the status of three key members of the unit on the eve of Sunday's game against the Buffalo Bills, the organization took action Saturday to add depth.
The Rams cut cornerback Coty Sensabaugh and promoted defensive lineman Morgan Fox from the practice squad to the roster.
Defensive ends Robert Quinn and William Hayes and tackle Michael Brockers have helped lead the Rams to a 3-1 record that put them atop the NFC West.
But they are trying to work through injuries that prevented them from practicing this week. All are listed as questionable for the game against a Bills (2-2) team that features dual-threat quarterback Tyrod Taylor and running back LeSean McCoy.
Ethan Westbrooks started last week in place of Hayes, and Matt Longacre also played extensively for a line that includes star tackle Aaron Donald.
End Eugene Sims and tackles Dominique Easley and Cam Thomas also are part of the rotation.
Asked Friday how concerned he was about the defensive line, Coach Jeff Fisher said the Rams had "a tendency of healing up."
By Saturday, apparently, one or more of the injured linemen were not physically sound.
The 6-foot-3, 263-pound Fox signed with the Rams as an undrafted free agent from Division II Colorado State Pueblo. He impressed during training camp and was productive in the final exhibition game at Minnesota, recording two sacks and pressuring the quarterback four times.
Sensabaugh, 27, signed a three-year contract in March worth about $15 million after playing four seasons with the Tennessee Titans. The Rams signed him to help offset the departure of free agent Janoris Jenkins.
Sensabaugh was guaranteed about $4.5 million this season.
Sensabaugh started two games opposite Trumaine Johnson, but he was replaced by second-year pro Troy Hill during the second game, against the Seattle Seahawks.
Cornerback E.J. Gaines' return from injury and Hill's development made Sensabaugh expendable, especially with a possible shortage this week on the defensive line.
Sensabaugh was inactive for last Sunday's victory at Arizona. Fisher said this week that Sensabaugh still had a role and had played "fine." He was inactive because of a need on special teams, and Sensabaugh did not have that background, Fisher said.
"But, it doesn't mean to say that he's not going to be active this week," Fisher said.
The questions surrounding the defensive line sealed Sensabaugh's fate for Sunday's game.
It will be the Rams' first at the Coliseum since their Sept. 18 home opener against the Seahawks.
"It seems like forever," Fisher said.
Players said they were looking forward to the home-field advantage fans created during exhibition victories over the Dallas Cowboys and Kansas City Chiefs and in the 9-3 victory over the Seahawks.
"It's a tremendous help," receiver Kenny Britt said. "There's something going on in that stadium that's something special."
The last time the Rams played at home, they were coming off a 28-0 season-opening loss to the San Francisco 49ers at Levi's Stadium.
Questions abounded regarding Fisher's status, quarterback Case Keenum's seemingly shaky hold on the starting quarterback position and the defense.
But the Rams shut down the Seahawks and did just enough on offense to win in front of nearly 90,000.
They then went on the road and defeated the Tampa Bay Buccaneers and Arizona Cardinals, ensuring both victories with big defensive efforts on the final play.
Now they are back to face an opponent that won its last two games in impressive fashion.
The Bills, under Coach Rex Ryan, ran all over Arizona in a 33-18 victory at Buffalo, and then went to New England and handed the Patriots a 16-0 defeat, New England's first shutout loss at home since 1993.
"They do a lot of crazy stuff," Rams running back Todd Gurley said of the Bills defense. "Try to mess with your brain, and they do a pretty good job with it."
Taylor leads a Bills offense that appears to have benefitted from a coaching change after two losses to start the season. Ryan replaced offensive coordinator Greg Roman with Anthony Lynn and the Bills have won two in a row.
Sunday's game is a homecoming for several Bills players and coaches who played at USC, including running back Reggie Bush, receiver Robert Woods and defensive backs Nickell Robey-Coleman and Kevon Seymour.
The game will be particularly noteworthy for Bush, the former Heisman Trophy winner. USC was ordered to disassociate from Bush as part of NCAA sanctions that resulted from an investigation that centered on Bush and his family for accepting cash and other benefits from would-be agents while he was playing for the Trojans.
The sanctions erased Bush from USC's record books but not from the memory of players who grew up watching him.
Gurley described Bush as "the best to ever do it in college."
Bush was inactive last week but might get an opportunity if a hand injury McCoy reportedly suffered in practice during the week prevents him from playing or limits him.