Every team has one: a player who just isn't quite delivering what is expected of him.
They come in all different forms.
Sometimes he's a player who was a high-priced free agent or a top draft pick that hasn't yet produced.
Sometimes he's a player who just can't stay healthy.
Sometimes he's a player who looks like an All-Pro one week, and very average the next.
And sometimes he's a player who is a combination of all three.
That's what makes each of these men enigmas for the front offices and coaching staffs of their respective teams.
And just so we're clear, being "an enigma" isn't necessarily a bad thing. Each of these players may turn out incredible seasons in 2012 and well beyond. But as of right now, they have been something of a head-scratcher.
Note: All of these entries have spent at least one season with their current clubs: There's not much to judge rookies and free-agent acquisitions on when it comes to their current teams.