With Christian McCaffrey, Jordan Mason out, 49ers turn ground game over to youth

With running backs Christian McCaffrey and Jordan Mason both possibly done for the regular season, the languishing 49ers are embracing a youth movement at the position.

Rookie Isaac Guerendo will be the new starter, and the 49ers’ biggest roster-filling move indicates a future-facing approach for a team that’s 5-7 and very unlikely to reach the postseason. Instead of signing a familiar veteran — 29-year-old running back Matt Breida is available, for example — the 49ers claimed 22-year-old Israel Abanikanda off waivers from the New York Jets. The new running back is now the team’s youngest player.

Consider the acquisition of Abanikanda, a fifth-round selection of the Jets in 2023, to be tantamount to a free draft pick for the 49ers. Because they claimed Abanikanda’s rookie contract off waivers, he’s under team control for two full seasons beyond this one at affordable base salaries just a smidge over $1 million.

“I liked him coming out of college,” 49ers coach Kyle Shanahan said. “I haven’t studied him a ton in the NFL, but he was a guy that I had good notes on from college and liked. And I know our scouting department thought he was the best guy out there being available. So in our situation, especially glad to get him here.”

Abanikanda’s mix of straight-line speed and solid size makes him at least somewhat reminiscent of Guerendo, who posted one of the most impressive size-speed combinations — a 4.33 40-yard dash at 221 pounds — of any running back to ever participate in the NFL scouting combine.

A lack of experience is the reason Guerendo lasted until the fourth round of the 2024 draft, where the 49ers snatched him. Guerendo, who converted from receiver to running back early in his time at Wisconsin, started only one game in his college career. He’s now preparing for the second start of his life at the position. It’ll come Sunday when the 49ers host the Chicago Bears.

“I think he is ready to go,” Shanahan said. “He got off to a late start with injuries in preseason. I thought he finished in those games well, especially that kick return he had versus the Raiders. Did some decent things when he started out but didn’t get a lot of carries, had some ups and downs but got better through everything. And then when he got the bulk of the carries, he only got better and he’s gotten better throughout the year. So I think he’s ready for this.”

Guerendo scored the 49ers’ only touchdown in their recent loss to the Buffalo Bills, taking a swing pass from quarterback Brock Purdy for six points (the play counted as a run since the throw traveled backwards).

“The more reps you get, the more you get the feel for it,” Guerendo said in the locker room Wednesday. “The more I’ve gotten, the more I’ve think I’ve caught on.”

Although the Bears rank No. 9 in overall defensive EPA (expected points added), their run defense is lackluster at No. 22. The 49ers, despite the blowout loss to the Bills, are coming off perhaps their best run-blocking performance of the season. Jaylon Moore and Ben Bartch again look on track to start at left tackle and left guard, respectively, after both Trent Williams (ankle) and Aaron Banks (concussion) missed Wednesday’s practice.

The final five games, at the very least, line up to be a valuable evaluation period for the 49ers — who’ll have a plethora of intriguing roster decisions to make after this season, regardless of how it finishes.

Banks, Bartch, and Moore are all pending free agents. Safety Talanoa Hufanga and linebacker Dre Greenlaw, who are both now back at practice as they work to come off injury lists, fall in the same boat. Hufanga, who tore a ligament in his wrist shortly after returning from a torn ACL early in the season, retook the field on Wednesday with a club on his right arm.

Both players can potentially help a 49ers run defense that has sunk to new lows even after last year’s precipitous drop. Against the run, the 49ers ranked No. 2 in EPA back in 2022 before sliding to No. 26 in 2023 and now No. 28 this season.

“You look at all of our losses, these last two weeks have been as bad as it gets,” Shanahan said of the run defense. “Especially when you give up the run game like we have in these last two weeks in the first half, the game’s almost over before it starts going into that second half.”

Star linebacker Fred Warner, who emphasized that he intends to finish out this season even on his fractured ankle, stands to see a boost playing alongside the likes of Greenlaw and Hufanga. The 49ers, Warner included, have struggled to deliver against the run on the back end. Second-year safety Ji’Ayir Brown had a particularly bad performance in Buffalo.

“It’s been frustrating because I know what it’s supposed to look like,” Warner said of the run defense, “and that’s not it.”

Extra points

• A reporter asked Shanahan if it’s a certainty that Bosa will be able to return this season from his oblique injury. “I’m not God, but I think he’s got a chance to play this week,” Shanahan said. “So I would think that would lead to getting a better chance each week. But I don’t know the answer to that.”

• McCaffrey, who’s expected to miss at least six weeks with his PCL injury, took to Instagram for his first public comments since getting hurt.

• Why hasn’t rookie receiver Ricky Pearsall caught any passes over the past three games? He had a big performance against Tampa Bay preceding this fruitless stretch.

“Ricky got a little banged up in Green Bay, battled through that a lot, still was able to play a lot through it and helped us out at punt return,” Shanahan said. “And I don’t judge much from that Buffalo game. I think we had six completions that were screens. There was nothing really with Ricky there. We had a chance to hit him downfield one time and he slipped, but that was nothing against him for that game.”

Pearsall will be a focal point of outside attention moving forward as the 49ers aim to, at the very least, build some positive momentum heading into the offseason.