Considering that our biggest trade assets by the time the deadline rolls around will be guys like Ayala, O'Day, Strop and Jim Johnson - I'm not so sure we'd be able to land that big fish that would help put us over the top and into the postseason anyway.
If we really start to fall out of it then our biggest trade chip (out of everyone) would be Jason Hammel. We still have another year of team control over him though (arbitration) so why would/should we trade him unless we are blown away by an offer?
Not saying we shouldn't try, just being realistic about it.
I think at best we could get a decent player in a package involving some sort of salary dump - i.e., Cubs trade us Soriano and a SP for a few mid-level prospects depending on the SP they include. The only one of their's that I would even want is Garza and not sure if they'd toss him in any Soriano deal without getting something good in return outside of just being rid of Soriano and his contract. IF Theo wanted to be rid of Soriano that badly though...I'd say anything is possible and we might as well check on a Soriano/Garza package.
More realistically though, we'll only get so much out of a few overachieving bullpen arms when relievers are so volatile one year to the next anyway. O'Day and J.J. are the only two guys in our bullpen that would probably bring back a decent prospect anyway - but that's just it, a prospect. Not likely a starting position player at either infield corner spot like we need.
My trade targets though, IF we are still in it and wouldn't have to give up our core top prospects, would be Justin Morneau (change of ballparks would be good for him) because the Twins owe him a lot of money and he is not hitting well at Target Field. Twins would want pitching in return - Tillman and Steve Johnson or some combination thereof would be a likely starting point (if I were the Twins GM).
Mat Gamel might not be a bad pickup even though he's out for the season with a torn ACL. Someone to look at during the offseason.
Placido Polanco if he proves to be healthy enough to play - Phillies wouldn't mind moving him and he wouldn't cost that much to acquire.
As far as SP's (not named Garza) are concerned:
Chien-Ming Wang or Francisco Liriano would be realistic targets for me that wouldn't/shoudn't take much to get.
Liriano (yes, laugh away) has actually lowered his ERA by 2 full runs since returning to the Twins rotation on May 30th. It was 8.47 and is sitting at 6.45 currently.
Our biggest trade chips are Manny Machado, Jonathan Schoop, Nick Delmonico, Parker Bridwell, etc.
We can't be afraid to trade some of those guys if we truly want one of the top players available.
Willingham should be our top target if he's available. He's getting on base and having a career year, something that could really help the Orioles and he's signed for only $14 million total over the next few years. LF would finally be fixed, and nobody knows if Reimold will ever play effectively again.
As for SP, Dempster, Garza, Greinke and Saunders could be targets, but if the Phillies make Hamels available, he's the guy you go after if you want a difference maker in your rotation that could swing the balance in the AL East.
A top three of Hamels, Hammel and Chen would be pretty nice for the stretch run.