Meanwhile , longtime defensive lineman Justin Smith is considering retirement .
While a solid nucleus of players remains , key contributors like Frank Gore , Michael Crabtree , Chris Culliver and Mike Iupati are set to be free agents .
Longtime defensive lineman Justin Smith is considering retirement .
While a solid nucleus of players remains , key contributors like Frank Gore , Michael Crabtree , Chris Culliver and Mike Iupati are set to be free agents .