The 49ers released Spence (concussion) on Tuesday.
Spence signed with San Francisco at the beginning of August to serve as depth after the team placed Maurice Hurst (biceps) on injured reserve. However, Spence picked up a concussion during the 49ers' preseason finale and won't make the team's initial 53-man roster. The veteran defensive tackle has appeared in only seven games over the last two years, totaling 10 tackles across 108 defensive snaps.