The 49ers will also place CB Emmanuel Moseley on injured reserve.
This shouldn’t come as much of a surprise after Mostert suffered a gruesome injury last night.
Mostert, 26, wound up signing on with the Eagles as an undrafted free agent out of Purdue back in 2015. He had brief stints with the Dolphins, Ravens, Browns, Jets and Bears before signing on to the 49ers’ practice squad in 2016.
The 49ers brought Mostert back on a one-year exclusive rights contract this past offseason.
In 2018, Mostert appeared in nine games and rushed for 261 yards on 34 carries (7.7 YPC) to go along with six receptions for 25 yards receiving and one touchdown.