SANTA CLARA, Calif. (AP) - The San Francisco 49ers have signed cornerback Keith Smith to a one-year contract, boosting their secondary a day after learning Nate Clements would be sidelined up to eight weeks with a broken shoulder blade.
San Francisco (3-4) also released receiver Micheal Spurlock and cut tight end Carson Butler from the practice squad.
Smith was released by Detroit before the season. The Lions selected him in the third round of the 2004 draft. Smith has played in 71 career games with five starts and 118 tackles, four interceptions, a sack, a forced fumble and one touchdown.