The 49ers are without safety Jaquiski Tartt, who remains on the active non-football injury list with a minor quad injury. L.J. McCray, a special teams standout in recent seasons, has been practicing with a heavy brace on his knee after having surgery in 2015.

Cornerback Will Redmond is wearing a brace on his right knee after suffering an ACL tear in October.

So this week San Francisco added to the secondary San Jose State alum Cleveland Wallace III, an undrafted free agent of the Texans off waivers. To make room on the 90-man roster, the 49ers released inside linebacker Lenny Jones, who signed with the Raiders Friday after working primarily with San Francisco’s third-team defense.

Wallace was on hand for Friday’s practice but did not participate. He will likely make his debut soon to take reps vacated by 49ers banged up with injuries.

“So we were really down three people in the secondary,” 49ers coach Chip Kelly said.

“All of them we feel will be back, but because they’re limited in their reps, we wanted to just get another set of legs in there just so we’re not wearing out the guys that are full-go and just trying to distribute the reps as much as we can.”