Dolphins signed SS Tyrell Johnson, formerly of the Vikings.
The 43rd pick in the 2008 draft, Johnson underachieved in Minnesota, starting just 27 of 49 games over four seasons. He was primarily a special teamer last year, playing roughly 30 percent of the defensive snaps. A liability in deep coverage, Johnson is a candidate to replace Yeremiah Bell as the Dolphins’ in-the-box safety.