San Francisco 49ers head coach Kyle Shanahan informed reporters that running back Raheem Mostert suffered a high-ankle sprain on Sunday night against the Los Angeles Rams.
"We'll see how it progresses," Shanahan said. "Most likely IR (for Mostert)."
Mostert will have company. Center Ben Garland left Sunday's game with a calf strain and will be "out for a while," according to Shanahan. He will "most likely" land on injured reserve later this week too. Shanahan said Hroniss Grasu would replace Garland until center Weston Richburg can return (see below).
Shanahan also provided the following injury updates.
- Safety Jaquiski Tartt suffered a groin strain. The 49ers will learn more this week about the severity of the injury.
- Tackle Trent Williams sustained an ankle sprain. The 49ers are awaiting more information on the severity of his injury. He was examined during the game for a head injury but ended up returning.
- Shanahan hopes to get running back Jeff Wilson Jr. (calf) back this week.
- Running back Tevin Coleman (knee) is a long shot to return off injured reserve this week. Shanahan has "a feeling it will be another week, but we'll wait and see, hold out hope for the end of the week."
- Richburg, who remains on the physically-unable-to-perform (PUP) list, is not expected to return until Week 12 at the earliest.
"Richburg, he had the knee from last year," Shanahan said on Monday. "And then he had shoulder surgery that happened during the offseason also. The shoulder surgery really set him back. I'm not sure which one has set him back the worst right now, but I know we're not going to get him until at least Week 12."
Mostert left Sunday's game in the third quarter. It was his second game back since returning from an MCL sprain he suffered during Week 2. Mostert tried to tough it out in the third quarter but couldn't continue after one play.
With Wilson inactive and Coleman still out, that left Jerick McKinnon and JaMycal Hasty to carry the load.
"I thought Jet did a good job running hard, doing what he's done for us every week, but Hasty was up for the challenge," Shanahan said after the game. "Got some fresh legs in there, and I thought he gave us some juice a little bit.
"We found out we didn't have Jeff. We found out later in the week with a tight calf, and Hasty got his opportunity, and from what I saw, I thought he really helped us."
Mostert finished the game with 65 rushing yards on 17 carries and two receptions for 11 more yards. He has registered 303 rushing yards and a touchdown on 51 carries (5.9 YPC) and 11 receptions for 150 receiving yards and another score through four games this season.