The Miami Dolphins have strengthened their depth at linebacker and likely their overall special teams play, too, with one move, signing veteran free agent Keith Adams, released by the Carolina Panthers over the weekend. Adams is expected to back up starter Channing Crowder at weakside linebacker, and can play the strong side as well. His biggest impact, however, might be on special teams, the area in which Adams has most excelled during his NFL career. A five-year veteran, Adams started all 16 games at weakside linebacker for the Philadelphia Eagles in 2005 and responded with a career season, registering 101 tackles. He had made only seven starts in his previous four seasons in the league. As an unrestricted free agent this spring, Adams signed with Carolina, and was the early favorite in training camp to fill the vacancy at weakside linebacker created by the exit of former starter Will Witherspoon to St. Louis as a free agent. But Adams did not readily assimilate the Panthers' defensive scheme and was beaten out for the starting spot by former Green Bay Packers starter Na'il Diggs. In Adams, the Dolphins are getting an undersized but active player who has demonstrated improvement every season of his NFL career.