SANTA CLARA – Wide receiver Torrey Smith sat out 49ers practice Wednesday due to back spasms.
Smith was plagued last week with his back condition as well as a toe injury. He played Sunday against the Cleveland Browns, but played only 48 percent of the team’s 56 offensive snaps.
Guard Alex Boone (knee) and linebacker Michael Wilhoite (ankle) did not practice with injuries coach Jim Tomsula described as "week-to-week." Boone has a right knee sprain and is not expected to return to action this season. Wilhoite availability for the remainder of the season also in question.
Outside linebacker Aaron Lynch and tight end Vance McDonald took part in limited practice after sitting out one week with concussions sustained in the 49ers’ victory over the Chicago Bears on Dec.