SANTA CLARA, Calif. (AP) — Rookie running back Trey Sermon cleared concussion protocol and will be able to play for the banged-up San Francisco 49ers this week against the Green Bay Packers.

The Niners have been hit by a string of injuries this season at running back with starter Raheem Mostert going down with a season-ending knee injury in the season opener, Jamycal Hasty sidelined by an ankle injury this week and Elijah Mitchell listed as doubtful with a shoulder injury.

But San Francisco got good news Friday when third-round pick Sermon was cleared to play after leaving last week's game at Philadelphia with a concussion. Sermon was a healthy scratch in the opener and got hurt on his only offensive snap last but could carry a heavy load against the Packers because of all the injuries.

Sermon had been limited Wednesday and Thursday at practice before being cleared on Friday.

“With the rules of protocol, you can’t do everything. But he’s been great all week,” Shanahan said. “Just what he has been able to do in individual, getting to do everything today. But you’re never fully sure of it until they clear it.”

Mitchell rushed for 104 yards in his debut in the opener before getting hurt last week. He didn't practice at all on Wednesday or Thursday before doing limited work Friday.

Because of all the injuries, Shanahan wants to wait before ruling Mitchell out but will only play him if he feels good and doctors say the injury can't get worse.

If Mitchell can't go, the Niners also have two other backs on the active roster in Trenton Cannon, who was claimed off waivers from Baltimore last week, and running back Jacques Patrick, who was signed off Cincinnati’s practice squad this week.

They also recently signed veterans Chris Thompson and Kerryon Johnson to the practice squad and could make either of them active on Sunday.

Getting all the new faces up to speed has been taxing on running backs coach Bobby Turner.

“You’ve got to do a lot of stuff. You can’t take everything in, so you just try to compartmentalize things and put it into certain groups and try to teach them a few groups of stuff,” Shanahan said. "You also can’t go around the clock as much as you need to because there’s a lot of work too that you have to recover and see from. But Bobby’s as good as anyone there is at it. I know whatever we ask of those guys, they’ll be prepared to do it.”

NOTES: DL Kevin Givens (ankle) is also out this week and will likely go on IR. ... DL Arik Armstead (adductor) didn’t practice and CB Emmanuel Moseley (knee) and DT Javon Kinlaw (knee) were limited. ... S Jimmie Ward, LB Fred Warner and T Trent Williams got rest days. ... The Niners also signed DL Eddie Yarbrough to the practice squad and released TE Jordan Matthews from the practice squad.

NOTES: DT Kevin Givens (ankle) was also ruled out for the game. ... DE Arik Armstead (adductor), DT Javon Kinlaw (knee) and CB Emmanuel Moseley (knee) are all questionable.


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