Jul 23, 2025; Santa Clara, CA, USA; San Francisco 49ers running back Isaac Guerendo (31) takes a handoff from quarterback Mac Jones (10) during the first day of training camp at SAP Performance Facility. Mandatory Credit: D. Ross Cameron-Imagn Images D. Ross Cameron-Imagn Images

49ers Must Start Viewing This RB as an Injury-Prone Player

Originally posted on San Francisco 49ers on SI
By Jose Sanchez | Last updated Aug 5, 2025 1:53 PM ET

Injuries have been running rampant on the San Francisco 49ers since training camp began.

They can’t even continue their kicker competition or have three quarterbacks because of the injuries. They need the spots from those positions to be used where they’re hurting.

One position that just took a hit with an injury is at running back. On Monday, Kyle Shanahan announced that Isaac Guerendo will be out for a few weeks due to a shoulder injury.

Shanahan didn’t specify what was wrong with his shoulder, but it’s significant enough to knock him out for a substantial time.

If the timeline he is out for holds up, Guerendo will miss all three of the preseason games. It’s not too much of a sting for him to miss the preseason.

Guerenndo is a proven enough player to do without it. However, after this latest injury, he is now officially recognized as an injury-prone player.

Guerendo isn't reliable

The 49ers must start viewing Guerendo as injury-prone moving forward. That means they can’t fully trust him to be reliable.

Since Guerendo was drafted, he has sustained six different injuries. This time last year, he injured his hamstring, which held him out for three weeks.

He barely managed to get into the preseason finale against the Las Vegas Raiders. Guerendo’s next injury (groin) occurred on Aug. 28, just days after the game.

After that one, Guerendo was finally quite on injuries. That was until Week 14, when he suffered a grade 1 foot sprain.

He didn’t have to miss time due to it, but he wasn’t healthy at all for the following game. That likely factored into him sustaining another injury in Week 15, a pulled hamstring.

Guerendo’s last injury of 2024 came in the regular season finale against the Arizona Cardinals. He was carted off with an MCL and ankle sprain.

And now, Guerendo is dealing with an unspecified shoulder injury that will keep him out for three weeks. It wouldn’t be shocking if it’s longer, given his luck.

The 49ers can’t depend on him any longer. The only way for Guerendo to be viewed as a reliable player is if he stays healthy for months.

But that’s a massive stretch, given the rate at which he gets injured. The 49ers will look at rookies Jordan James and Corey Kiner to step up in the meantime.

Do not be surprised if these players start to supplant Guerendo, especially if he is out for longer than three weeks.

This article first appeared on San Francisco 49ers on SI and was syndicated with permission.

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