Lot of risk here but its the 4th round. UDFA invited to rookie mini camp and impressed enough to earn a contract for training camp. Gruden likes big RBs and Warren fills that nicely at 6'2 240lbs +. OK speed for his size and excellent agility. Some articles call him a FB others say RB that can take snaps at FB. He gives the Raiders options for use which should help him make the roster.