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.