49ers may need to add to thin D-line

SANTA CLARA, Calif. – Earlier Wednesday, San Francisco 49ers coach Jim Harbaugh said it was possible the team will add to its thin defensive line this week in the form of a roster move.

After practice, it became evident why such a move could happen. Starting defensive linemen Justin Smith (shoulder), Ray McDonald (biceps) and Glenn Dorsey (hamstring) all did not practice.

Smith and McDonald are likely to play Sunday at Tennessee, although McDonald is still getting used to playing with his injury he suffered in Week 5. Dorsey’s hamstring injury is not expected to be too serious. But teams are always cautious with hamstring injuries because they can quickly get worse. It wouldn’t be a shock if Dorsey sits out this week. If that’s the case, Tony Jerod-Eddie would start.

A potential candidate to be added to the active roster would be Mike Purcell, who is on the 49ers’ practice squad.

Rookie Quinton Dial, who is practicing for the first time this week, is a long shot. He likely needs more time to practice before he is ready to play. Along with rookie defensive lineman Tank Carradine, cornerback Eric Wright and receiver Mario Manningham, the 49ers have until Nov. 5 to either activate or shelve Dial for the year.

Harbaugh said all four players are just starting the process of returning.

“The players are, our coaches are [working] to get them acclimated back into playing 11-on-11 football,” Harbaugh said.