The 49ers wouldn’t have beaten the Seahawks this past Thursday night without rookie running back Isaac Guerendo.

The 49ers had a 20-point lead, but starting running back Jordan Mason left the game with a sprained AC joint in his shoulder. Guerendo was the only decent running back left on the roster — Patrick Taylor Jr. is on the team to play special teams, not run the ball. And for most of the second half, Guerendo struggled. He gained just 23 yards on his first 9 carries.

In that time, the Seahawks cut their deficit from 20 points to just five. It seemed like the 49ers were on the verge of blowing another double-digit lead to a division opponent. All the Seahawks had to do was stop Guerendo two more times, force an incomplete pass on third down and lead one more touchdown drive. Doable.

But the Seahawks couldn’t stop Guerendo one more time. On his 10th and final carry, he broke through the right side of the 49ers’ offensive and sprinted 76 yards to put the game away.

Guerendo is the only running back on the roster who could have made that play. He’s probably the fastest player on the entire team — he was a sprinter in college. Head coach Kyle Shanahan compares him to Raheem Mostert.

Does that mean Guerendo can carry the 49ers’ run game if Mason misses time with his shoulder injury?

Why not?

Guerendo doesn’t seem to have Mostert’s vision and decisiveness between the tackles, but he certainly has Mostert’s burst to the sideline. In the 49ers’ outside-zone blocking scheme, Guerendo is uniquely equipped to take advantage of George Kittle’s blocks on the edge.

If the 49ers give Guerendo 20 carries, he could take one or two to the house. That’s how talented he is.

Let’s see how the 49ers use him against the Chiefs next Sunday.