It is unclear whether the players tested positive for COVID-19 or were in close contact with someone who did.
Pepper has served as the team’s long snapper for 12 games. The 49ers do not have a long snapper on their practice squad.
Grasu has appeared in nine games for the 49ers this season, making three starts. He has seen action on 215 offensive snaps and 17 on special teams.
The 49ers removed running back Austin Walter and practice squad fullback Josh Hokit from the COVID-19 list Monday.