49ers vs. Colts: 3 key Niners who’ll make all the difference in Week 7

2. 49ers RB Trey Sermon

In the wake of Raheem Mostert’s season-ending injury, San Francisco’s run game has been left in the hands of a trio of rookies. Elijah Mitchell, Trey Sermon, and quarterback Trey Lance have all been used to cover ground through five weeks.

Despite some shared run responsibilities, Mitchell has been the clear feature back in 2021. But that doesn’t mean much. He only has 189 yards in three games and has dealt with injuries, if that helps spell out how insignificant the rush attack has been. Sermon, his fellow rookie, has barely seen an opportunity to make strides this season, which is perplexing considering the 49ers typical preference for more equal tailback treatment.

What will it take for head coach Kyle Shanahan to go back to utilizing a dual-threat running back tandem? Mostert has been paired up with Matt Breida and Tevin Coleman in the past to create a two-punch approach to ground transportation, and now is no time for Shanahan to abandon that approach.

Sermon’s biggest competition in the run game might be his fellow Trey on the team. Lance has 133 rushing yards to Sermon’s 135 and has proven his power and grit on the ground. If the rookie QB gets the start against the Colts, Sermon will have to work overtime to flex his ability to be impactful for the Niners offense.

If instead Jimmy Garoppolo is under center, keep an eye on Sermon. A breakout game for him could provide the spark that the offense needs to breathe some life back into their season.