The 49ers elevated Vaughn from the practice squad to the active roster ahead of Thursday's game versus the Rams.
Vaughn got in the mix this past Sunday against the Bears when Isaac Guerendo exited early due to a foot sprain. All three of Vaughn's offensive snaps occurred in garbage time with San Francisco holding a massive lead, resulting in two carries for four yards. Guerendo's status for Week 15 remained in limbo until earlier Thursday, when Adam Schefter of ESPN reported that the running back "feels good" and intends to play versus L.A. If Guerendo is able to suit up, he likely would pace the team's backfield, with Patrick Taylor and then Vaughn the pecking order behind him.