... sleeper should be, by definition, tucked away under a serious blanket of almost complete anonymity. If you have heard his name more than once, chances are, he's not a sleeper. If your buddy tells you, "keep an eye on Brian Price of Penn State—he's a beast"! Ummm, that's NOT a sleeper. However, if the guy eating peanuts at the bar says to you, "ya know, I think that kid Porter from LaTech could be the next Willie Parker", and you find yourself saying "who"? Then, THAT is a sleeper. These guys may or may not be at the NFL Combine. They may or may not be called on the first day, but, eventually you will know their names. And, when that happens, look out because you may very well be a witness to history in the making.

Bleacher Report - NFL