Dolphins' latest RB additions reveal a much deeper roster failure

Miami Dolphins general manager Chris Grier | Jasen Vinlove-Imagn ImagesThe loss of Alexander Mattison left a hole in the Miami Dolphins' running back room. Mattison may not have made the final 53, but he was giving the coaching staff every reason to keep him.

Running back is not a huge issue for the Dolphins. Cornerback is, tight end maybe, and of course, the offensive line. Everyone knew the Dolphins would add another running back to replace Mattison, but no one expected what GM Chris Grier would do.

Miami added free-agent running backs Aaron Shampklin and Mike Boone to the roster to replace Mattison. The problem? Neither can provide what Mattison does.

Chris Grier's moves bring more…