Todd Gurley didn't play because of a knee injury on Sunday, but it was hard to tell.
Backup C.J. Anderson – a street free agent until Wednesday – looked like a Pro Bowl running back himself in the Rams' 31-9 win over the Cardinals. He carried the ball 20 times for 167 yards and a touchdown. The Cardinals gave up 269 rushing yards in the game, a season-worst.
"The run defense was just horrendous," coach Steve Wilks said.
The Falcons rushed for 215 last week and run-stopping issues have been a recurring theme throughout the year. The Rams averaged 6.6 yards per carry on 41 attempts a week after Atlanta averaged 8.0 yards per tote. Wilks, a defensive coach, was asked if the repeated issues are getting under his skin.
"It's like a virus right now," Wilks said.
Anderson isn't a speed demon but the lanes were wide and he broke multiple tackles. His longest run was a 46-yard scamper from the Los Angeles 5-yard-line in the fourth quarter. The Rams capped the 95-yard drive with a touchdown just three plays later.
Anderson has been released three times this year – by the Broncos in April, the Panthers in November and the Raiders 12 days ago – but looked at home with the Rams.
"If you watch the tape, that was nothing different than my game from what I've done plenty of times," Anderson said. "The big boys played really great up front. Obviously I get nothing going if it wasn't for them. That's been my game since I've been in (the league) for six years. If you ever paid attention to any football with C.J. Anderson in it, you wouldn't be surprised at all."
Backup running back John Kelly added 10 carries for 40 yards while wide receiver Brandin Cooks (27 yards), tight end Gerald Everett (16 yards) and wide receiver Robert Woods (15 yards and a touchdown) were used effectively on fly sweeps.
"We've got to do a better job," defensive tackle Corey Peters said. "No ifs, ands, buts about it."
ROSEN PULLED FOR SECOND STRAIGHT WEEK
Quarterback Josh Rosen left the game in the fourth quarter of the lopsided loss, the second straight game it happened. He finished the contest 12-of-23 for 87 yards without a touchdown or an interception.
Rosen does not like leaving games but said he forced Wilks' hand by playing poorly.
"It's frustrating, but it's my fault," Rosen said.
Wilks didn't want Rosen to get any more beat up than he was to that point. Rosen injured his arm on an incomplete pass midway through the third quarter and had it wrapped on the sideline, but returned to the game without missing any action.
"It feels like a bruise," Rosen said. "It hurt a little bit but I'm fine now."
CUNNINGHAM CARTED TO LOCKER ROOM
Rookie left tackle Korey Cunningham left the game with a foot injury in the fourth quarter and was carted to the locker room. He was quickly ruled out for the remainder of the game. Will Holden replaced him the rest of the way.
Tight end Ricky Seals-Jones left with a shoulder stinger in the first half and didn't return.
COOPER TAKES OVER AS PUNT RETURNER
New signee Pharoh Cooper took over as the punt returner. However, Los Angeles was only forced to punt one time and Cooper returned it for just one yard.
Running back T.J. Logan remained the kickoff returner but all six Greg Zuerlein kicks went for touchbacks.
Images from the Week 16 matchup at State Farm Stadium

Cardinals running back David Johnson (31) pulls in a touchdown pass from wide receiver Larry Fitzgerald as Los Angeles Rams free safety Lamarcus Joyner (20) pursues during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) is hit by Los Angeles Rams cornerback Aqib Talib and defensive back Nickell Robey-Coleman (43) during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals quarterback Josh Rosen (3) gets the throw off as Los Angeles Rams wide receiver Josh Reynolds (83) makes the hit during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz. The Rams won 31-9.

Arizona Cardinals wide receiver Larry Fitzgerald greets Los Angeles Rams quarterback Jared Goff after an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz. The Rams won 31-9.

Arizona Cardinals running back Chase Edmonds (29) stiff arms Los Angeles Rams wide receiver KhaDarel Hodge (11) during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) leaves the field after an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz. The Rams won 31-9.

Arizona Cardinals wide receiver Larry Fitzgerald greets Los Angeles Rams running back C.J. Anderson after an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz. The Rams won 31-9.

Arizona Cardinals quarterback Josh Rosen (3) throws as Los Angeles Rams strong safety John Johnson (43) pursues during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams cornerback Troy Hill (32) can't make the catch Arizona Cardinals wide receiver Chad Williams (10) defends during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals outside linebacker Haason Reddick (43) celebrates his sack against the Los Angeles Rams with defensive end Chandler Jones (55) during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals quarterback Josh Rosen grabs his elbow after taking a hit from Los Angeles Rams linebacker Dante Fowler (56) during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams quarterback Jared Goff (16) bobbles the snap as Arizona Cardinals outside linebacker Haason Reddick (43) pursues during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals quarterback Josh Rosen (3) is sacked by Los Angeles Rams defensive end Aaron Donald during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams wide receiver Robert Woods (17) is tackled by Arizona Cardinals outside linebacker Deone Bucannon (20) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams head coach Sean McVay talks with side judge Rob Vernatchi (75) against the Arizona Cardinals during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals running back David Johnson (31) is hit by Los Angeles Rams linebacker Dante Fowler (56) during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

DT Corey Peters and the Cardinals defense on the tackle

Los Angeles Rams quarterback Jared Goff (16) hands off against the Arizona Cardinals during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals quarterback Josh Rosen (3) looks to throw against the Los Angeles Rams during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

QB Jared Goff under pressure

Los Angeles Rams running back Todd Gurley watches from the sidelines against the Arizona Cardinals during the second half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams cornerback Aqib Talib (21) makes a hit on Arizona Cardinals wide receiver Larry Fitzgerald (11) for an incomplete pass during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

DE Benson Mayowa strips the ball from Rams QB Jared Goff to force a fumble

Arizona Cardinals head coach Steve Wilks greets quarterback Josh Rosen (3) during the first half of an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Jalen Tolliver (17) can't make the catch as Los Angeles Rams cornerback Aqib Talib (21) defends during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) is hit by Los Angeles Rams strong safety John Johnson (43) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams running back C.J. Anderson (35) falls into the end zone for a touchdown against the Arizona Cardinals during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams wide receiver Robert Woods (17) is hit by Arizona Cardinals outside linebacker Deone Bucannon (20) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Rosen scrambles for extra yardage against the Rams

Los Angeles Rams tight end Gerald Everett (81) makes a catch as Arizona Cardinals outside linebacker Haason Reddick (43) defends during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) runs as Los Angeles Rams defensive back Marqui Christian (41) defends during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams running back C.J. Anderson (35) scores a touchdown as Arizona Cardinals outside linebacker Deone Bucannon (20) and Arizona Cardinals defensive back David Amerson defend during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Cardinals wide receiver Larry Fitzgerald (11) celebrates his touchdown pass with teammates against the Los Angeles Rams during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Cardinals running back David Johnson (31) pulls in a touchdown pass from wide receiver Larry Fitzgerald (11) during the first half of an NFL football game as Los Angeles Rams outside linebacker Samson Ebukam (50) pursues, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams running back C.J. Anderson (35) runs against the Arizona Cardinals during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals quarterback Josh Rosen (3) is tackled by Los Angeles Rams inside linebacker Cory Littleton during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Rams running back John Kelly (42) is hit by Cardinals linebacker Gerald Hodges during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Larry Fitzgerald fights for extra yards against the Rams

Rams tight end Gerald Everett is hit by Arizona Cardinals free safety Antoine Bethea (41) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Cardinals tight end Ricky Seals-Jones (86) is hit by Los Angeles Rams inside linebacker Mark Barron (26) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

K Zane Gonzalez hits an early field goal to put the Cardinals ahead 3-0 in the first quarter

Cardinals wide receiver Larry Fitzgerald (11) throws a touchdown pass against the Los Angeles Rams during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams quarterback Jared Goff (16) throws over Arizona Cardinals linebacker Deone Bucannon (20) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Los Angeles Rams quarterback Jared Goff (16) celebrates after scoring a touchdown against the Arizona Cardinals with offensive tackle Andrew Whitworth (77) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

LB Deone Bucannon falls on the fumble

Los Angeles Rams quarterback Jared Goff (16) scores a touchdown against the Arizona Cardinals during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Cardinals wide receiver Larry Fitzgerald (11) tries to elude Los Angeles Rams cornerback Marcus Peters (22) during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

RB David Johnson sprints into the end zone after catching a pass from Larry Fitzgerald

Cardinals kicker Zane Gonzalez (5) watches his field goal split the uprights against the Los Angeles Rams during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

The defense celebrates an early turnover

Cardinals defensive end Benson Mayowa (91) forces Los Angeles Rams quarterback Jared Goff (16) to fumble as he makes the sack during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Cardinals linebacker Deone Bucannon (20) recovers a fumble as Los Angeles Rams running back C.J. Anderson (35) defends during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals free safety Antoine Bethea, right, tackles Los Angeles Rams tight end Gerald Everett during the first half of an NFL football game, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals cheerleaders perform prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals cheerleaders perform prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals cheerleaders perform prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Santa made it to State Farm Stadium for the game between the Cardinals and Rams

Arizona Cardinals cornerback Patrick Peterson (21) gives a thumbs up prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) greets head coach Steve Wilks prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals cornerback Patrick Peterson (21) warms up prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.

Arizona Cardinals wide receiver Larry Fitzgerald (11) laughs prior to an NFL football game against the Los Angeles Rams, Sunday, Dec. 23, 2018, in Glendale, Ariz.