Who Will be the 49ers' Backup Running Back this Year?

The backup running back is an important player on the 49ers.

That's because their starter, Christian McCaffrey, gets injured frequently. That's what happened when he played for the Carolina Panthers and it's what happened last season on the 49ers. He missed all but four games due to bilateral Achilles tendonitis and a torn PCL. And so his backup, Jordan Mason, led the 49ers in rushing.

This offseason, rather than re-sign Mason who was a restricted free agent, the 49ers traded him to the Minnesota Vikings for a fifth-round pick. Now, it's unclear who McCaffrey's backup will be.

It could be Isaac Guerendo. He started three games last season as a rookie when both McCaffrey and Mason were injured, and he averaged an impressive 5.0 yards per carry. Unfortunately for Guerendo, he got carted off the field with a knee injury in the 49ers' final game of the season. So he may not be durable.

Guerendo is a good backup running back because he's explosive, so if you give him five carries, one could be a long touchdown run. But he doesn't seem built to start in place of McCaffrey if he misses time.

That's why the 49ers drafted Jordan James in Round 5. James is a much more durable and physical running back than Guerendo. So if James learns the 49ers' offensive system quickly, he could leapfrog Guerendo as the 49ers' No. 2 running back.

Because at this point in McCaffrey's career, he needs to split carries with someone who can pick up the tough yards, and that's James, not Guerendo.

Don't be surprised if James is the 49ers' backup running back this year.