Labeling prospects as "overrated" going into the draft often makes it seem as though it's the player's fault that his ability was overestimated. This is not what we're doing here.
However, there are a few players in this year's class that have received higher ratings than they should. And they will carry those too-high expectations into their pro careers if selected at the top of the draft.
Sometimes a good college player is ranked at the top of a weak position group -- a player who should be a mid-second-round pick can be pushed into the mid-to-late first round if a team wants to get the best of a shallow pool. Players' values are also overestimated when their potential for greatness is given too much weight vs. the inconsistency that player showed against better college competition.
The following draft prospects on defense are all likely to be longtime NFL players. But I believe they've been overrated during the evaluation process. For my list of overrated offensive prospects, click here.
Eli Apple, CB, Ohio State: He had a successful couple of seasons with the Buckeyes as a press corner. He has the size (6-foot, 200 pounds) and speed (4.4-second 40-yard dash at the NFL Scouting Combine) that teams covet at the position. But Apple will need to get stronger to lock down more physical NFL receivers, and scouts have questions about his natural ability to find the ball in the air. I expect him to play in the league for some time, but ranking him among the top 15 picks in this class might overestimate his ability as a consistent playmaker.
Robert Nkemdiche, DT, Ole Miss: It's not as though Nkemdiche hasn't shown talent on the field. He performed quite well at the combine, too, confirming the athleticism everyone saw on Saturdays. But with an inconsistent motor and lack of production, it doesn't make sense to consider him a top-20 prospect. And in today's NFL, character issues are front and center on teams' minds, so Nkemdiche's off-field issues could hurt him. If he puts it all together on the field and stays out of trouble off the field once he enters the NFL, some team might get a great find. But I'll keep projecting him as a second-round pick, as it better displays the risks associated with the selection.
Sheldon Rankins, DT, Louisville: There aren't many one-gap pass-rush tackles in the draft, but Rankins is one of them, and he's being projected as a top 12-15 pick. His combine performance was excellent, which only improved his stock. However, his lack of bulk and inconsistent ability to shed better blockers inside make him a liability as an every-down player. Good coaching should help him improve in this area, and maybe he will become a constant threat to the quarterback. But he's really a better value in the late-first/early second round than he is in the top half of Round 1.
A'Shawn Robinson, DT, Alabama: It was a tough ask for a college lineman to move Robinson off the ball, and he had enough athleticism to make plays against lesser competition. But he plays too upright, which will make life difficult for him when he meets veteran NFL offensive linemen with experience staying low and playing with leverage. Will he be a strong rotational player who can eat up space and challenge linemen? Yes. Will he be the sort of difference-maker (especially rushing the pass) expected by teams and fans if picked in the top 15 overall? Not unless he plays lower and has his motor running hot on every play.
Follow Chad Reuter on Twitter @chad_reuter.