Duncan and Barton are basically untradeable right now.
Duncan isn't hitting and can't field which makes his trade value complete squat. This is the big reason he needs to go down, play 1st base at Memphis and work on his swing there. Then he might have some trade value if the swing comes around.
With Barton being a Rule 5 guy, the Cardinals have to keep him on their roster for some specific amount of time or Cleveland gets his rights back. (at least, that's what I've read). Which makes trading Barton problematic, since I don't even know if they can trade a Rule 5 player. If they could, the other team would have to keep Barton as well for however long, or it's back to Cleveland he goes.
IMO, Barton is a fine bench player and perfectly capable of the occasional start when someone does need a night off.
What gives the Cardinals trade depth is the pitching and OF prospects moving right along in the minors. The question is what do the Cardinals need?
Pitching = There are plenty of relief guys available considering how well our middle relievers turned starters have done this season. If Carpenter gets back, Wainwright, Carpenter, Wellemeyer, and Lohse are a reasonable starting 4. The question is whose the 5th starter. It's looking like Mulder might not make it back so he's out. Pineiro is having a leg issue. Looper needs to go back to the middle relief role when Carp gets back. Perez/Franklin closing/setup working out just fine. Heck, we're looking good at pitching.
OF - we're set.
C - could use a better bat than LaRue as the backup catcher. Supposedly good prospect at Memphis who is close
1B - Is there any point in commenting?
2B - Kennedy has got to find his bat. He's not worth the dineros if he's not hitting. Miles is doing just fine filling in there.
SS - Izturis is solid defensively. The question mark is his bat. But he is hitting as well as Duncan right now
So, yes, Ryan at SS for the future.
3B - Glaus needs to find his bat at home. If that comes around, 3B should be alright as well.
So what should the Cardinals trade for with all that OF depth?? 2B?? C??
It just doesn't seem like the Cardinals should worry about making a trade unless it's for starting pitching if the hurt guys can't make it back. Thing is - whose gonna give up a decent starter. Of course, Duncan is darn good at making sub-par guys look like All-Stars again, so maybe they could find another career to salvage. But then, the Cardinals wouldn't need to give up those quality OFers and could keep them from the rest of the league.