With D.J. Coles, WR out of Virgina Tech, you get a player that has the size to be a contributor at 6'3, 225 pounds. In fact, he has in the past weighed in at 235 pounds. However, you also get a player that has been battling a right knee injury which has required 3 knee surgeries and was likely the main cause for him not being drafted.
The thing that jumps off the tape for Coles is that he is a physical receiver after the catch. He doesn't shy from finishing off runs and has a tendency to fall forward for extra yards while being tackled. He has the ability to find the soft spots in zones and if he can translate that skill to the NFL he will be an effective receiver.
Stats wise, Coles had a decent senior season for the Hokies. He had 25 receptions in 6 starts but managed to accumulate 387 yards for an average of 15.48 yards per reception and he added a team-leading 6 TD's as well.
The Raiders wanted to get a receiver in the draft but their draft board didn't fall out that way. As soon as the draft was over they got on the phone and reeled in Coles. He has good size and a competitive nature to fight for a spot, and if his knee can hold up he just might be able to make the Raiders squad.
If you want a highlight that will get you excited, here is D.J. Coles with a devastating block that shows his physicality.