The injury bug has taken a big bite out of the ' backfield. The team lost starter for the year in Week 1 due to a knee injury, and in Week 2, all three of their top backs went down. (shoulder) is listed as doubtful for Sunday's https://www.brownsglintshop.com/Joe-Schobert-Jersey primetime matchup with the , while fellow back (ankle) has already been placed on injured reserve.With all those backs down, it looks like Kyle Shanahan will be turning to rookie in Week 3. According to , Sermon is expected to start for https://www.brownsglintshop.com/Eric-Murray-Jersey the 49ers against Green Bay. If that's the case, he'll be the third starting running back for the club in three weeks.The 2021 third-round pick has carried the ball just once this season and https://www.brownsglintshop.com/Joe-Thomas-Jersey exited last week's game due to a concu sion. He's since cleared protocol, which has cleared a path for him to make his first significant dent in the NFL. During his final collegiate season at Ohio State, Sermon averaged 7.5 yards per carry. While he hasn't lived up to his draft billing thus far -- he was a healthy scratch in Week 1 -- the https://www.brownsglintshop.com/Larry-Ogunjobi-Jersey young back will get an opportunity to take the reins in a 49ers offense that loves to run the football. Even with all those injuries, the Niners entered Week 3 third in the league in rushing attempts (66) https://www.brownsglintshop.com/Duke-Johnson-Jersey .That said, even if Sermon is the first backup, the 49ers could continue to rotate backs, especially after activating veteran from the practice squad. San Francisco also has running backs and on the roster.