From ESPN insider
OVERALL TRAITS
Size-Strength-Speed
Lacks ideal height for the position. Is built with a tightly-wound muscle tone and is a physical player. Plays with a scrappy demeanor. Is both quick and fast and when he gets into the open field he could win foot races consistently. Shows sudden quickness ideal for the perimeter.
Instincts/Recognition
Is a reactive player both physically and mentally. He sees the game, understands it and utilizes those instincts to make plays. Possesses a very good knack and exceptional first step to be able to transition from a backpedal to jumping the thrown ball or aggressively filling an alley on a run. Really does a nice job of seeing through the receiver to the quarterback in zone concepts. Places himself in proper position based on alignment and understanding of the scheme.
Coverage Skills
Thrives at keeping the ball in front of him, but can transition and run with vertical routes as well. Fluid and athletic in his movements. Quick and fast and does a good job recovering to get into position when lined up in tight coverage. Has tight, balanced footwork and smooth transitional skills. Is in and out of his pedal without a lot of wasted motion. Ball skills are one of his better attributes. Shows he can lock down and effectively play both off and press man and receivers have to really work to try to gain separation. Very good mirroring skills and balance in and out of breaks. Tracks the ball very well on deep routes. Would be somewhat concerned vertically if matched up against bigger, physical targets who can out jump him.
Run Support
Is active in willing, but size could be limiting. Plays in run support the same way he does in coverage - with attitude. Is a low tackler with some pop. Lacks the imposing structure to be a devastating tackler based off measurables. Is more than capable of this area.
Bottom Line
We're a little surprised Shelley is not being more heavily recruited at this stage. While he lacks ideal height for the perimeter, he is very productive and confident in his skill set. He's a good little player that has big upside as a return specialist. This may be where his biggest impact is.
Underclassman Eval
STRENGTHS: Shelley displays good quickness and ability to change directions and transition. Shows a good feel in zone coverage to get depth and close quickly. Reads the QB's eyes well. Can come off of primary assignment and make a play. Very willing in run support. ... AREAS OF IMPROVEMENT: Lacks ideal size at this point in time. Will need to improve size. Can struggle at times in man coverage versus bigger receivers but is still physical to work to disrupt at top of receiver stem. ... BOTTOM LINE: Shelley is an athletic prospect who plays with good discipline and awareness. Could potentially be a BCS prospect at a low to mid level with continued physical development over the next couple of years.