The San Francisco 49ers are working out running back Artavis Pierce, per Aaron Wilson. The team will be without featured back Raheem Mostert for about eight weeks. He will land on injured reserve after sustaining some chipped cartilage in his knee during Sunday's Week 1 win over the Detroit Lions.
San Francisco 49ers are working out running back Artavis Pierce, according to a league source. Running back Raheem Mostert placed on injured reserve with chipped cartilage in his knee
— Aaron Wilson (@AaronWilson_NFL) September 14, 2021
Rookie Elijah Mitchell, a sixth-round draft pick, replaced Mostert in Sunday's game and rushed for 104 yards and a touchdown on 19 carries. The team's other rookie running back and a third-round draft pick, Trey Sermon, was inactive. JaMycal Hasty had one carry for three yards and a touchdown.
The Chicago Bears signed Pierce (5-11, 208) as an undrafted free agent out of Oregon State in 2020. He carried the football six times for 34 yards with a rushing touchdown through five games last season.
Chicago waived Pierce on August 31 but re-signed him to its practice squad. He was released on September 8.