Is Isaac Guerendo playing today? 49ers injury update and fantasy replacements

If the San Francisco 49ers want to defend their NFC West title, they must defeat the Los Angeles Rams in Week 15. However, the team enters Thursday Night Football with health concerns, specifically in the backfield.

Already down reigning AP Offensive Player of the Year Christian McCaffrey and his primary backup, Jordan Mason, vaulting Isaac Guerendo atop the depth chart. But the talented rookie running back sprained his foot in San Francisco's Week 14 38-13 victory over the Chicago Bears.

Guerendo's injury, combined with the short rest week, casts doubt on his status for the Niners' pivotal divisional showdown with the Rams. Given the circumstances, it's unfortunate news, especially considering the 24-year-old was thriving as the clear focal point of San Fran's offense against the Bears. He recorded 128 scrimmage yards (78 rushing, 50 receiving) and two touchdowns on 17 touches before exiting the contest.

Will the 49ers have Guerendo at their disposal versus the Rams?

Is Isaac Guerendo playing today? 49ers injury update

Despite entering the primetime clash with a questionable tag, Guerendo "plans to play," per ESPN's Adam Schefter.

Not only does Guerendo intend to suit up, but he reportedly and insistently 'feels good.' That's an encouraging development for the 49ers because it will be an all-hands-on-deck effort as they try to keep pace with a red-hot Rams offense. But should a pregame setback prevent him from taking the field, how would San Francisco's backfield shake out?

Here's how the 49ers' running back depth chart looks sans Guerendo.

Please, for heaven's sake, be good to go, Guerendo. As you can see, it gets rather dire for the 49ers without the 2024 fourth-round selection in the mix. They recently brought back and called up veteran backups Patrick Taylor Jr. and Ke'Shawn Vaughn from the practice squad. San Fran also claimed undrafted second-year pro Israel Abanikanda off waivers from the New York Jets. With this misfit bunch of characters, we could see more Deebo Samuel "wide back" carries, though those have been highly ineffective this season.

Isaac Guerendo fantasy football replacements

While Guerendo is on track to be available, fantasy football managers might want to have an alternative. Moreover, even if active, there's likely an increased risk of an in-game setback or reduced usage. Regardless, getting ahead of the curve and being ready to pivot is a solid idea. It's particularly worthwhile since Week 15 represents the first round of the playoffs for most leagues.

Below are a few widely available yet potentially valuable free-agent backs probably sitting on your waiver wire.

Patrick Taylor Jr., San Francisco 49ers

You may not feel great doing it, but Taylor steps into a sizable and fruitful role if Guerendo isn't in the lineup. The former immediately assumed workhorse duties for the 49ers upon the latter getting hurt, rushing for 25 yards and a score on seven attempts. Facing a porous Rams run-stopping unit in a game with a respectable 48.5-point over/under (per ESPN Bet), whoever starts has a prime matchup.

Sincere McCormick, Las Vegas Raiders

Regardless of Alexander Mattison's anticipated return, McCormick has staked his claim as the Raiders' RB1 and appears fit for the job. The UDFA rookie has been Las Vegas' most effective runner this year since -- by far. He's racked up 31 touches over the past two weeks, translating to a reasonable 12.3 expected fantasy points per game.

Isaiah Davis, New York Jets

Three-down tailback Breece Hall is on the wrong side of questionable for Week 15. So, Davis and Braelon Allen may share the Jets backfield for another week. The skilled rookie tandem operated in a virtually even timeshare, yielding 16 touches for both backs.