You'd think the Dolphins would be set at cornerback. They have three good ones. Sean Smith and Vontae Davis were good enough to start 16 and nine games, respectively, last year as rookies. Will Allen was their top cornerback when he went down with a knee injury in Week 7. But teams never can have enough good cornerbacks, and there are no guarantees Allen will be back. He recently was busted for driving under the influence of alcohol and has had off-field problems before. The Dolphins also declined to bring back free-agent nickelback Nate Jones.