49ers: 4 players who benefit most from NFL free agency signings

No. 2: 49ers Running Back Raheem Mostert

Amid all their injuries, the Niners ranked 22nd overall in run blocking last year, according to Football Outsiders.

Not exactly the kind of production Kyle Shanahan would want from a run-first offense.

So it’s partially impressive running back Raheem Mostert averaged 5 yards per carry over eight games played last year, although him dealing with multiple injuries didn’t work in his favor. And Mostert’s average was also influenced by some long, long runs.

Offenses are so “hand in glove,” it’s hard to talk about one unit without it being completely influenced by another.

In Mostert’s case, along with the remainder of San Francisco’s runners, the team’s reinforcement of the offensive line along with bringing back fullback Kyle Juszczyk helps matters a ton.

Trent Williams remains arguably the best left tackle in football after earning his eighth Pro Bowl nod last season. While expensive, Williams’ presence makes a massive difference. So does bringing aboard Alex Mack, whose 70.2 run-blocking grade from Pro Football Focus last year is significantly higher than Weston Richburg’s mark of 57.3 back in 2019.

The 49ers choosing to get strong again in the trenches serves a player like Mostert well, and he’ll use that first- and second-level blocking to his advantage as long as he can stay healthy.