Ray, I agree he is a diamond in the rough. For various reasons, I have followed the AFC West fairly closely the past few years. IMO, the Chargers thought they got a steal when they selected Martin in the 4th round. Going by just measurable, he appeared to be an unbelievable prospect and he flashes his physical talent at times. I believe the Chargers want him back, but won't go overboard on a contract to keep him. I know the Pats are running more 4-3 now but I believe Martin could play in both a 3-4 or a 4-3. In a 3-4, he can play DE and some NT and in the 4-3 he would be DT. He is very strong against the run but despite his quickness, he gets very little pressure as a pass rusher. I don't know if he just needs to work on technique or what it is. Right now, all he has is a bull rush(very quick and powerful bull rush) If the light ever goes on for him, you are looking at a poor man's Haloti Ngata. A DE in a NT body. If he comes to NE, hopefully their DL coaches can mold him into something. He has an unbelievable amount of physical talent. I just don't know if he will ever reach his potential. He still seems raw after 4years in the league.
On the other hand, there is Tommy Kelly. I am pretty sure his time in Oakland is just about done and he has shown the ability to dominate(when he isn't doing something stupid). If Al Davis never signed TK to a Seymour like contract( I am exaggerating slightly), then I think everyone in Oakland would be happy with TK. Not overjoyed because he has lots of untapped potential also, but still they wouldn't want to drive him to the airport the way they do now. Kelly got the big contract and underperformed and became one of the poster children for the dysfunctional Raiders franchise. I think Reggie McKenzie will right the ship and hopefully Kelly will find a home (in New England for the right price) where they can take advantage of his skills. I know BB always liked him, so hopefully there is a fit there.
IMO, Martin has more potential but is still very raw. Kelly has performed much better in his career but still didn't reach all his potential yet. Either one should be able to give NE a big rotational DL for either the 3-4 or 4-3. Right now Kelly offers more pass rush and Martin is probably better against the run.
That is one reason I thought the Pats ought to look at Matt Shaughnessy before he signed with the Cards. At 285 lbs he is smaller than Kelly or Martin but is very stout against the run and also has shown some decent pass rushing skills (7 sacks in 2010) albeit sporadically.