Speaking to the media on Monday, general manager John Lynch noted that the "gravity" of the charges is not lost on the organization.
Foster is facing three felonies stemming from an alleged attack on his girlfriend -- domestic violence with an allegation that he inflicted great bodily harm; forcefully attempting to prevent a victim from reporting a crime; and possession of an assault weapon.
Lynch said if the charges are proven true, "he won't be a part of this organization going forward," per NFL Network's Jim Trotter.
On Monday, Lynch confirmed that Foster will continue to be kept away from Niners offseason workouts. The team is working with the young linebacker to create a structure away from the facility, the GM added.
In addition to the criminal charges, Foster is subject to potential NFL discipline under the league's personal conduct policy, which mandates a six-game suspension for a first-time domestic violence offense.