Which of these MLers is not like the other?

I play in a few leagues, but my main one is a H2H points-based league where the scoring rules so favor the pitchers that any fool who can hurl a ball can help you.  That means the competition for top pitchers is huge. So this is the one league, and I mean the ONLY league, where I emphasize pitching in my minor league draft.  15-man ML rosters, so you can speculate deep.  What I do is take what John says and only go for B, B+, A-, or A players.  I look for top of the rotation starters, and guys who dominate.  If only every fourth guy comes through, I'm set.

Well, my draft is done, and here is who I have.  I like them all, but maybe you can point out one or two who is not quite as good as the rest.  I need trade bait, after all, so your opinions will help!

So which of these guys would you trade, and which ones would you hang onto for dear life?  In batters, and I do have some, I have:

Joe Mauer, C -- Yeah, still eligible
Brian McCann, C
Eric Duncan, 3B
Chris Nelson, SS
Stephen Drew, SS
JJ Hardy, SS -- Can you guess what position I speculate on?
Javier Herrera, OF

Then for pitching I have:

Felix Hernandez
Chad Billingsley
Jeff Niemann
Justin Verlander
Denny Bautista
Ervin Santana
Chuck Tiffany
Greg Miller

So which of these is not like the others, as that old Sesame Street song went?  Which ones would you willingly trade, and which ones would you keep no matter what?