Rams can’t afford to take injury plagued 49ers lightly

One day, perhaps next season, the Rams and the San Francisco 49ers will finally, legitimately renew a rivalry that was thought to be reborn when the Rams returned to Los Angeles.

That didn’t happen in 2016, when both teams struggled under since-fired coaches. But the arrival of offense-minded whiz kids Sean McVay and Kyle Shanahan was supposed to reenergize what had once been one of the NFL’s most intense division competitions.

The Rams quickly turned into a playoff team, but the 49ers continued to founder until they acquired quarterback Jimmy Garoppolo, who won all five of his starts to end the season. Among those victories was a season-ending victory over the Rams, a game that did not mean much because McVay rested all of his starters in preparation for the postseason.

NFC West preseason buzz revolved around the Rams and ascending quarterback Jared Goff, and a 49ers team poised to take a big step with a full season of Garoppolo.

Instead, the meh factor continued after Garoppolo suffered a season-ending knee injury in Week 3. Four weeks later, the Rams easily handled 49ers quarterback C.J. Beathard in a 39-10 victory.

On Sunday the Rams face an injury ravaged 4-11 team now led by rookie quarterback Nick Mullens.

Star power might be lacking, but it is an important game for the Rams.

With a victory at the Coliseum, they will clinch the No. 2 seed in the NFC and a bye through the wild-card round of the playoffs.

“This is something that we can’t afford to take lightly,” said McVay, whose team ended a two-game losing streak with a victory last Sunday over the Arizona Cardinals. “It’s very important for us to come out ready to go.

“Continue to carry some momentum that we were able to establish.”

Goff appears to have played his way through a three-game minislump, but running back Todd Gurley’s left knee issue could force the Rams to again start C.J. Anderson. The sixth-year pro rushed for 167 yards and a touchdown in 20 carries against the Cardinals.

Goff has passed for 28 touchdowns, with 12 interceptions, for an offense that ranks second in the NFL, averaging 424.1 yards per game. The Rams are third in scoring, averaging 31.9 points per game.

Receivers Robert Woods and Brandin Cooks each have eclipsed 1,100 yards receiving, and tight end Gerald Everett is continuing to emerge as a reliable target.

Rams defensive tackle Aaron Donald is within three sacks of tying Michael Strahan’s NFL season record of 22½.

So he has added motivation to chase down Mullens, a rookie who has started the last seven games.

Mullens has passed for 10 touchdowns, with seven interceptions. In last Sunday’s 14-9 loss to the Chicago Bears, he completed 22 of 38 passes for 241 yards, with an interception.

The 49ers suffered more injuries in that defeat.

Leading rusher Matt Breida and receiver Dante Pettis, the team leaders with five touchdowns each, both were declared out against the Rams.

Tight end George Kittle has a team-best 79 catches for 1,228 yards and four touchdowns. He has had three 100-yard receiving games, among them a 210-yard performance against the Denver Broncos.

“Kittle is going to be Kittle,” cornerback Marcus Peters said. “We’ve just got to stop him, get off the field on third down and give the ball to the offense.”

End DeForest Buckner has 12 sacks for a 49ers defense that ranks 10th, giving up 344.6 yards per game. The 49ers are allowing 25.8 points per game, which ranks 24th.

Christmas spirit

A few days before Christmas, Goff and Gurley chipped in to buy each offensive lineman a Polaris Ranger utility terrain vehicle.

Goff said the gifts were “quite expensive” but going in with Gurley — who signed a $60-million extension before the season — made it manageable.

“Splitting it helps a lot,” Goff said. “But anything for those guys. They deserve it.”

Etc.

Rams players were given Monday and Tuesday off. They resume practice Wednesday.

gary.klein@latimes.com

Follow Gary Klein on Twitter @latimesklein