Trey Sermon had two fewer snaps than he did against Green Bay, but it was clear he was more comfortable and that Shanahan and his assistants trusted him more. Still, the team hasn’t had a true third-down back after JaMycal Hasty went down with a high ankle sprain in Week 2.

For the second straight game, Kyle Juszczyk was the running back of choice on third downs or when the 49ers were in a hurry-up mode. Or the 49ers had a running back split out wide with no one in the backfield in those situations. The last two games have been heavier in three-receiver formations (56 percent of plays) than the first two (32 percent) when the 49ers had their full (or at least fuller) complement of tailbacks.

Related players: Elijah Mitchell

With Mitchell out with a shoulder injury, Sermon ran 19 times for 89 yards on the day. Meanwhile it was Juszczyk who was targeted four times and had four catches for 41 yards. Sermon was targeted once on the day. There will be some workload and role questions in this backfield when Mitchell is able to play again.

49ers RB JaMycal Hasty has a broken collarbone.

Related players: Jerick McKinnon, Kyle Juszczyk, Austin Walter

Hasty was trending in the wrong direction over the last few weeks, and his injury means he can be dropped in typical leagues. With Raheem Mostert, Jeff Wilson and Tevin Coleman out, it should mean a big workload for McKinnon going forward, at least until Mostert is able to return. Fullback Juszczyk could get more involved and Walter is a name to keep an eye out for despite being at the bottom of the depth chart.

San Francisco 49ers running back Raheem Mostert has finalized a new contract with the team, his agent announced Monday.

Earlier this month, agent Brett Tessler announced he had requested that the 49ers trade his client because of unproductive contract talks. However, the situation changed on Monday as Tessler tweeted:

"Just finalized a new deal for Raheem Mostert with the San Francisco 49ers. Happy we got things worked out and looking forward to him having another great season there. Thanks to the organization for taking care of him."

Related players: Jerick McKinnon, Kyle Juszczyk, Tevin Coleman

Details of the contract were not immediately known, but before the deal, Mostert was scheduled to be paid a base salary of $2.575 million this season and was due $2.875 million in 2021 as part of a three-year contract he signed last year. Mostert will be a high-upside back in any given week, but given the nature of the 49ers’ hot-hand approach at the position, this may be a frustrating situation for fantasy owners.