The Nats are in a funny spot. For many baseball analysts you are either a buyer or a seller. Buyers are teams with a good shot of making the playoffs (or really now with the play-in game, with a good shot of winning a division). Sellers are everyone else. For them everyone else should purge themselves of any 30+ year old veteran near the end of a contract for whatever organizational filler they can get. It's the way to win.
Except it's not. Well, not explicitly. Look through the rosters of the teams that are winners right now and you'll see that these teams are by far mixes of draft picks and free agent signings. The "prospects" they have gotten back in deals when they were out of the playoff mix are few and far between. Part of the reason is that there just aren't enough of these type of deals done to matter to your team. How many veterans can you sell off a year? 2 or 3? Usually for low-level stuff in return. And that stuff has in general gotten worse over the years as teams realize the value (and in some respects over-value) their young talent and refuse to part with the best of it.
So you don't usually directly win by trading off veterans for young players. For every John Smoltz there are a dozen Kyle Drabeks. How do you win then by doing it? Well there are two indirect ways. One is based on a terrible flawed theory that I hate and want to punch everyone whenever I see someone hinting at it. The other one helps a little.
The helps a little one is getting bad. You trade your veteran players. This makes you a worse team. You win fewer games. You get higher draft picks. The end. It's a cycle that matters but only if you can get so much worse that the draft picks you get are more than just a couple spots away, or if you are so bad that you might get one of the top slots. The Nats were masters of this. In 2008 they were fighting for the worst spot. They dealt away Rauch and Ayala and when they couldn't get anyone to bite, they outright cut Felipe Lopez and Paul LoDuca. They finished the season on a 15-31 slide (6-17 at the very end) which got them Strasburg. In '09 they traded Hanrahan, Beimiel, Nick Johnson, and Ronnie Belliard among other pieces and crashed so hard (12-31) that even a 7 game win streak to end the year couldn't get them out of last. Hello Bryce Harper.
Of course you can see both of these mattered because it was the difference in getting a generational talent or not. Now the Nats would be fighting between what? A 20th pick and a 16th pick? At that point I'm not sure getting worse really matters. It can't hurt, I guess.
The other way, the one that angers my blood, is what I like to call the "money bucket" theory. In this theory, there is only so much that is going to be spent on baseball. Money spent on veteran players is money that can't be used to sign better free agents next year, help resign your own guys, do work and sign guys internationally, and use on player development. It's better to get value on your dollar when you win so you have as much money as possible to do everything else. THIS IS NONSENSE. BASEBALL OWNERS ARE SUPER RICH AND COULD THROW AS MUCH MONEY AT THE TEAM AS THEY WANT. THERE IS NO MONEY BUCKET THAT ONCE IT IS EMPTY THERE IS NO MORE MONEY FOR BASEBALL.
If you go along with this line of thinking you are complicit in your ownership being cheap bastards. You, therefore, are also a bastard.
Anyway, I've rambled off topic a bit. The Nats are not going to get much better by selling veterans off. The return won't likely be good. The amount they would get worse (especially dealing a closer) would be minimal. Their owner seems committed right now to spending money to win. Most importantly the Nats aren't a rebuilding team. They are a team built for now that is hopefully having an off-year. Next year they want to, expect to, win.
The Nats have a good pen. Not a great one. We don't know if Storen is going to come back. I've expressed great admiration for Clippard but he has been used heavily and is getting up there in age (well, in baseball age).
If the Nats weren't ready to win then I'd say trade Soriano anyway. Who cares if a bad team has a bad pen? But the Nats have a core that they believe can win. Ramos, Desmond, Zimm, Werth, Bryce, Strasburg, Gio, ZNN, Clipp. They have young guys they think can help right away Krol, Rendon. They have a window set up right now until about 2016-7. At that point Werth is too old, Zimm is probably too old, and they can't keep everyone else signed. They want to try in 2014 & 2015, not trade away talent with the hopes of finding something that works in the meantime all for the chance at maybe being slightly better in 2016 than they would be anyway.
Unless Soriano can return something that helps as much as Soriano would next year it makes no sense to trade him. That is assuming you think this Nats core is still good enough to win a division in the next couple years. I do.