49ers roster: 4 rookie backups who’ll be starting by end of 2021

Trey Lance #5 of the San Francisco 49ers (Photo by Ezra Shaw/Getty Images)
Trey Lance #5 of the San Francisco 49ers (Photo by Ezra Shaw/Getty Images) /
3 of 4
Trey Sermon, San Francisco 49ers
San Francisco 49ers running back Trey Sermon (28) Mandatory Credit: Darren Yamashita-USA TODAY Sports /

No. 2: 49ers Running Back Trey Sermon

This one is a bit misleading, but it’s important to recognize just how reliant Kyle Shanahan’s offense is going to be this year upon the ground attack.

In years prior, Shanahan has gone with a running back committee, frequently featuring the hot hand in the second half after opening up the game with a rusher who’ll technically start but won’t always get the lion’s share of carries.

To start the year, it seems likely Shanahan will deploy the veteran running back, Raheem Mostert, who remains the Niners’ top rushing weapon.

At least for now.

Related Story: Why Trey Sermon steals 49ers starting RB job in 2021

But Mostert, too, has an injury history and missed eight games last year. Even if he stays healthy, San Francisco will likely want to keep Mostert fresh. Especially down the stretch.

Hence, a chance for third-round rookie running back Trey Sermon.

Sermon was relatively quiet during the preseason, getting 16 rushes for 63 yards and averaging 3.9 yards per attempt. One should expect that to change, though, once the regular season commences and Shanahan opens up his playbook fully.

Mostert is likely to get the home-run carries in the second half of games late in the season, but look for Sermon to be the primary option and starter by that point.