Biggs: 49ers add CB depth with Smith

The San Francisco 49ers signed veteran cornerback Kevin Smith to a one-year contract, providing them with some depth now that Nate Clements will miss six to eight weeks with a broken shoulder blade.

Smith was a third-round draft pick of the Detroit Lions in 2004 and was released by the new coaching regime just before the start of the season. He was primarily a nickel back for the Lions over the past five seasons.

To make room for Smith, the Niners released wide receiver Michael Spurlock.

The club elected not to place Clements on injured reserve, but if he hits the outer limit of his projected rehabilitation, he will not play again this season. Clements lost his starting job to Tarell Brown last week, just after Brown had signed a contract extension with the Niners.

San Francisco also cut loose tight end Carson Butler from its practice squad.

Follow me at Twitter: BradBiggs