San Francisco 49ers cornerback Walt Harris could miss the upcoming season after tearing a ligament in his right knee. Harris, 34 and a 13-year pro entering his fourth year with the 49ers, was injured during Tuesday's practice in a collision with receiver Dominique Ziegler. Harris will need surgery on his anterior cruciate ligament, which is at least partially torn. Harris, who has 35 career interceptions and four touchdowns, also played for Chicago, Indianapolis and Washington.