Getty This Raiders' UDFA has a unique chance to make the 53-man roster. In a Las Vegas Raiders secondary filled with question marks and opportunity, former UCLA and USC cornerback John Humphrey has emerged as the undrafted free agent (UDFA) with the best shot at cracking the final 53-man roster. Bleacher Report recently highlighted Humphrey as the most likely UDFA to survive final cuts, and for good reason. USC UDFA John Humphrey Has Ideal Traits to Make Raiders’ 53-Man Roster Standing at 6’2″