Beginning the year as RB2 behind Jordan Mason, who also landed on IR, the round 4 pick out of Louisville turned in some good tape as a speedy change-of-pace back, including a 99-yard game against the Seattle Seahawks, but was never supposed to be more than that when the team was fully healthy.

Fortunately for Guerendo – and unfortunately for the 49ers – that is no longer the case, as the rookie is expected to earn his first-ever start in Week 14 against the Chicago Bears.

A tough task? You bet, but in the opinion of the running game coordinator, Chris Foerster, Guerendo is up for the task, as the 49ers have made it his mission to get ready for when his number gets called.

“Oh, he is more than ready. That’s been the good thing. Not having to jump in right away. You guys heard that, I liked him from the beginning. The kid had that burst, that quickness and he’s been able to be eased into it, not easing right now. So you still have to be careful, he hasn’t played a full load in an NFL game up to this point,” Foerster told reporters.

“Now is he going to be able carry the load for all four quarters like [RB] Christian [McCaffrey] has done in the past or not? I don’t know that we’ll have to see as we go. And the other guys, 32’s [RB Patrick Taylor Jr.] been here for a good while. 31’s done a good job. Obviously, we’re excited for Isaac, and we’ll see how it plays out. But it’s definitely going to be a challenge for us and challenge for him because he’s going to have to tote the mail for us, and he’s going to have to do a lot of things over a longer period of time than he’s done it up to this point.”

With just 42 carries to his credit as a pro, Guerendo is a relative unknown heading into Week 14. While that might feel daunting for fans, it’s ultimately good news for 49ers fans, as they might be able to get the jump on Chicago like they did with Mason in Week 1.

Isaac Guerendo fits the 49ers’ desired running back prototype

Asked about how Guerendo fits into the 49ers’ scheme, Foerster noted that Kyle Shanahan has a need for speed at the position, as having that “home run threat” in the backfield helps to open up the offense.

“Well, you kind of are what you are. Speed is nice. If you can get it, it’s important. Being a good back and having a good feel for the running game, hitting the right lanes, doing things like that. He set all sorts of records in Washington with [Former RB] Alfred Morris and Alfred we all know is not a speed demon. So there’s that balance between a good runner that understands it. It took [Miami Dolphins RB] Raheem [Mostert] a while to get going in this offense before the speed really showed up. It is nice to have that home run threat. It is nice, as you saw, when Isaac has broken some runs – the end of the Dallas game, the end of the Seattle game, where all of a sudden we talked about it, we called it the ‘angle assassin.’ You think that you’re on the right angle, but with that speed you’re able to get that burst and get further and more yards than most people would. So, it is nice to have speed.”

Can Guerendo turn in more big plays out of the backfield like his efforts in Seattle? Potentially so, and if he can do that consistently enough, who knows, maybe he could become the next Mostert and force Shanahan to play two backs when CMC gets healthy in the future.