Executing a perfect draft strategy is not as easy as simply selecting the best player available on the board, especially once you start factoring in off-field issues and injuries into the mix.

Take St. Louis Rams defensive back Janoris Jenkins or Quinton Coples of the New York Jets, both of which had off-field issues entering the 2012 draft, and yes, both were taken early by their respective teams.

Jenkins has been a hit for St. Louis, while Coples has seen limited time in his rookie year. 

Selecting such polarizing players can be a major gamble. Just ask the Dallas Cowboys, who have the oft-disciplined Dez Bryant on their roster. It can be boom or bust.

Every draft has this type of player, including a few already constituting the 2013 NFL draft.

Matt Miller breaks down the three players that general managers must think extra hard before they draft.