SAN FRANCISCO, Oct. 4 (UPI) -- San Francisco cornerback Mike Rumph is expected to miss the rest of the season with a broken right arm.
Coach Dennis Erickson said Monday Rumph will undergo surgery this week.
Rumph, who missed the two previous games with a strained groin, got hurt trying to make a tackle in the first half of Sunday's 24-14 loss to St. Louis.
A first-round selection in the 2002 draft, Rumph has posted three interceptions in 33 career games. Last season he made 64 tackles in 13 games.
Shawntae Spencer will replace Rumph in the 49ers' starting lineup.