21. Justin Houston, LB, Chiefs
When healthy, Houston is arguably the best edge player in the league. He had 50.5 sacks in 54 games before a knee injury in the second half of 2015 slowed him down. He was thought to be on the right track to a full recovery after a postseason clean-up procedure, but instead he ended up needing ACL surgery, and an early-season return is in doubt. What’s not in question: Before the surgery, Houston was the most dominant outside linebacker in the game. His blend of speed and power along with his rare flexibility make him nearly impossible to block with just one man. Pity the offensive tackle that falls victim to Houston’s patented dip-and-rip pass rush move.