This is not only the biggest weakness on what is a pretty good defense, but the biggest weakness on this team right now.
The Dolphins have one solid starter in strong safety Yeremiah Bell. However, Bell is 32 and has become more of a box-type safety who is limited in space. Bell piled up 114 tackles last season and still plays downhill in the run game. He runs the alleys well as a force player. He is an excellent inside-out tackler who is effective getting ball carriers down inline or out in space.
The bigger issue is at free safety, where the projected starter is Tyrone Culver. He has been a part-time player for Miami over the past two seasons and really has not shown enough to make you believe he can move into a starting role. He has excellent size for the position. He can cover some ground in center field when playing in deep coverage. Ideally, though, you would like your free safety to be able to get people lined up in the middle of the field when he is in the deep third, and this is an area where Culver is going to struggle. He does not have the necessary experience to run the defense. He is going to have trouble getting himself lined up, let alone trying to get everyone else aligned.
Culver is not a quick-reacting safety in the little I have seen him on film. He is slow to break from the middle of the field. His lack of experience hinders his ability to read routes quickly and get a jump on the football. He does not always take good angles against the run or the pass.
What is even more alarming for Miami is the complete lack of depth at the position. The Dolphins have only three other true safeties on their roster. One of those is rookie Reshad Jones, whom they took in the fifth round of the draft. Jones will have to contribute early and often in the sub packages if this unit is not going to be exposed in 2010.