SANTA CLARA -– Nose tackle Glenn Dorsey left the practice field Friday evening after sustaining an arm injury during the early portion of the 49ers' workout.
A member of the 49ers training staff examined Dorsey’s left biceps while he flexed his arm during the preliminary examination on the sideline before heading to the locker room. There was no update on Dorsey's condition.
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Dorsey started 13 games last season after taking over for Ian Williams, who sustained a fractured lower leg in the 49ers’ Week 2 game at the Seattle Seahawks.
Williams remains on the physically-unable-to-perform list as he continues his rehabilitation.
Defensive linemen Justin Smith and Ray McDonald have not practiced during training camp. Smith (shoulder) and McDonald (biceps) underwent offseason surgeries.
Defensive lineman Demarcus Dobbs has missed a couple of days of practice with an undisclosed injury.
Tony Jerod-Eddie, Tank Carradine, Quinton Dial, Mike Purcell and Lawrence Okoye are the only healthy defensive linemen on the 49ers’ 90-man roster.