Cornerback is viewed by many as one of the Lions' top needs this offseason, but not because they are lacking bodies. They have Chris Houston back after he signed a long-term deal around this time last year, and they also have Darius Slay returning after joining the Lions as a 2013 draft pick. Also under contract are Bill Bentley and Jonte Green. Bentley could be the Lions' nickelback again, and Green is looking to get into the mix for more playing time after making only two starts last season.
In addition to the four players under contract, the Lions will likely tender exclusive-rights free agent Chris Greenwood, who showed some potential when he joined the 53-man roster at the end of last year. It remains to be seen if they will re-sign Rashean Mathis, who was the Lions' top cornerback in 2013, but he could also potentially be back.
Depth is not the issue here for the Lions. They simply need more consistency from their cornerbacks and general improvement across the board. Houston, for example, had a rough 2013, perhaps because he dealt with various injuries throughout the season. He needs to return to his 2012 form this year. The Lions also need Bentley, Green and Greenwood, who are all entering their third year in the NFL, to take a step forward in their development. The same goes for Slay, who is entering his second year in the league.
Need going forward?
Considering they have so many young cornerbacks already, I don't think there is a need to go out and spend a first-round pick on another player at this position. If a cornerback turns out to be the best player on the board, then I guess you take him, but the real need here is to sign a veteran with a proven track record. Perhaps that means re-signing Rashean Mathis, or perhaps that means trying to sign one of the top available free agents. In any case, adding a veteran would provide some insurance in case Houston doesn't bounce back and in case the young cornerbacks don't improve this offseason.
As for the draft, I don't have a problem with adding another cornerback in a later round. The hope is that the new defensive coaching staff will get the most out of the cornerbacks already on the roster, but having another guy around to develop in case the recent draft picks don't work out isn't a bad idea. I just don't think spending a first-round pick on a cornerback and potentially having to rely on him as a rookie is a wise strategy.
For the Lions, signing someone with a proven track record, using a mid-round draft pick on a cornerback and hoping that the guys already on the roster actually get better seems to be the way to go this offseason.