He was drafted because of his 40 time and in his first two years he looked like an athlete and not a football player, showing little ability to move laterally and adjust while attempting to cover, so he got burned a lot. In 2012 he was thrust into action due to injury and actually performed solidly, and last year he was pretty darn good though never a game changing play guy. He's like a lot of guys who hit the market who are good but not great, so the team didn't make any push that I know of to re-sign him, especially after investing in Jamar Taylor and Will Davis at CB that draft. The only knock I can give you on Carroll is that he seems to get dinged up a lot, though last year he played through what looked like some really painful hits.
You won't find a great amount of love for him around here, too many Dolphin fans write the book on a guy based on his first few appearances, not on the player he eventually became. He was a starting corner on a defense that almost never got beat deep, and that says something.
