Will the 49ers go to a more pass-heavy approach without Christian McCaffrey and Jordan Mason?

The San Francisco 49ers faced some tough injuries this past week, as they lost both star Christian McCaffrey and top backup Jordan Mason to various issues, depleting their depth at running back.

McCaffrey, who suffered a PCL injury, is expected to be out for the remainder of the regular season with a six-week recovery, while Mason, who suffered a high-ankle sprain, is expected to hit Injured Reserve this week ahead of Sunday’s contest against the Chicago Bears.

That has left the 49ers, who have often been lauded for their depth at running back, with just one of their four running backs that they began the season with, as McCaffrey, Mason, and Elijah Mitchell are all out.

The lone remaining back? Rookie Isaac Guerendo, who has seen a good amount of volume already this season, rushing for 296 yards and two touchdowns on 5.9 yards per carry.

Without McCaffrey, the 49ers have posted solid rushing numbers but haven’t been as efficient on the ground as they’d like to be, hurting the offense at times.

Now, San Francisco is down both McCaffrey and Mason, which begs the question: will they look to be more pass-heavy to alleviate the stress off their running back group?

Looking back at the games when Mason dealt with his shoulder issues, the 49ers did rely upon Guerendo a good amount.

The rookie got his first extensive workload back in Week 6 against the Seattle Seahawks, rushing for 99 yards on 10 carries after Mason couldn’t play for the majority of the second half with a shoulder injury.

The 49ers did seem to go more pass-happy in the second half, even with the lead, but relied on Guerendo to close the game out, and the rookie delivered with a 76-yard run that eventually led to a Kyle Juszczyk rushing touchdown to seal the 36-24 win.

In Week 8 against the Dallas Cowboys, Guerendo got his biggest workload yet as Mason dealt with the recurring injury mid-game, going for 85 yards and a touchdown on 14 carries, while the 49ers went for 223 yards and two touchdowns on 36 carries in the 30-24 win.

So, when they’ve had to go to him, the 49ers have relied on Guerendo at times, but it’ll be interesting to see how things change over the full course of a game.

How has head coach Kyle Shanahan seen Guerendo’s progress this season?

“I think he is ready to go,” Shanahan said about Guerendo taking on the lead role. “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, I think. Did some decent things when he started out, 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, I want to say some more versus Seattle, he only got better and he’s gotten better throughout the year. So I think he’s ready for this.”

“I think just the urgency of running the ball in the NFL, I think it takes guys some time. You start to get a feel for it the more, if you’ve got the right stuff, the more you get reps, the more you can adjust to it. How hard you’ve got to hit stuff, how quick those holes close, how when there is a hole how you have to hit it full-speed and can’t hesitate at all or it closes like that. We’ve seen that stuff get better in practice and we’ve seen it carry over into games.”

Behind Guerendo, the 49ers will rely on recently-signed running back Israel Abanikanda, as well as practice squad back Patrick Taylor Jr., but it’ll be a big test for the rookie running back as he looks to carry the load for San Francisco.