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.