Looks like someone's trying to dump Matt Clement or Bronson Arroyo down here in beautiful Washington, DC. Hopefully Clement, since I have serious questions about his ability to pitch like a big boy, and because Arroyo can be useful
Many reasons to not expect such a deal, despite what appears to be a natural fit between buyer and seller:
* Brian Lawrence, whose injury created the opening in DC's rotation to begin with, is an innings-eater. He's a 14-game winner, a #4-type guy. Why tear apart the fabric of your team in order to replace a .500 pitcher that you essentially got for free? (Vinny Castilla = for free.) I don't see that, especially when the NL East will be even harder for DC to win this season.
* DC is also sitting on Alfonso Soriano, who still won't move to the outfield. Though it's taboo to trade a positional superstar for a pitcher, even a good one, you'd think any major deal would have to involve a resolution to the Soriano saga. (Soriano for Kerry Wood?) Jose Vidro, the Nats' starting 2B, has been mentioned in the Clemmoyo rumors, but that makes no sense for the Sox, who already have 2B taken care of and have no need for an injury-prone guy with limited double-play abilities (unless you count grounding into them).
* Acquiring a reliable .300/20/80 type like Johnson at 1B wouldn't necessarily be an improvement over Kevin Youkilis. Not coronating Youk as an All-Star at all, just saying the incremental improvement isn't worth a 14-17 win starter. Ditto for Church, whom I really like, over Nixon. It gains us youth and resistance to injury, that's all.
The only deal I see the Nats making is for Vidro plus another player (perhaps Church), just to make room for Soriano at second. If the deal hinges on taking Vidro, though, the Sox likely wouldn't do it unless it's for Clement's entire salary... that way the "talent" deal is Church for Clement, and the "albatross" deal is Vidro's knees for Clement's salary. Maybe the Sox throw in a prospect, seeing as both Vidro and Church are capable starters. Either way, it doesn't really make enough sense to do.