49ers vs. Lions: 4 players who let Kyle Shanahan down in Week 1

No. 3: 49ers Running Back Trey Sermon

Speaking of Trey Sermon, Kyle Shanahan told reporters after the game he wanted to dress four running backs, but the rest of the roster needs ultimately convinced him to dress three, therefore leaving Sermon out of the mix that ultimately had to feature Elijah Mitchell and JaMycal Hasty after Raheem Mostert’s game-ending injury.

But it’s what Shanahan said on Monday that should be revealing:

"It’s not an easy decision, but that’s part of the NFL. But it’s a matter of time. We haven’t got through a year here where we haven’t started at least four different backs. And now we’re into Week 2 and he’s up regardless and I expect him to come in and play at a high level and just keep getting better because there’s a reason we drafted him and we’ve got a lot of confidence in him."

Shanahan is looking to give Sermon some confidence but also has expectations the rookie hasn’t quite been able to make yet.

Especially considering Mitchell was mostly held out of the preseason with an injury, while Sermon was mostly healthy.

Of all the current San Francisco players in Shanahan’s doghouse, Sermon is the likeliest to break free.

Mostly out of necessity.