Well gambling on how Willingham did this year to see if you could increase his value is risky bet. Turning 32 in February, he's not young. He's also coming off surgery. Expectations were that he'd bounce right back into his usual productive self but that's probably a bit optimistic. Of course that risk is fine when you are paying Josh 3-5 million dollars a year, but that would be ending soon. Josh was out of option years, and next year would be a free agent. He was going to get a decent raise if he was any good this year. The Nats weren't likely to dole out a bunch of cash for Josh's 33+ years. Trading him now, when the Nats could be sure he still had value, was an understandable move.
The curious thing about the deal isn't that the Nats traded Josh Willingham, however; it is who the Nats got back. You would hope they Nats would get either (1) a couple of allright starting pitching prospects (quantity, people!), or (2) a decent major league contributing player better than what the Nats have now. Instead the Nats got one pretty good relief prospect and a major league hitter not better than what they have.
Henry Rodriguez is a classic relief prospect. Super fast pitcher. High K's (11.4 K/9 in minor leagues in 2008, 15.2 in 2009, 13.4 2010) High BB's (6.5 BB/9 in 2008, 7.2, 3.8). Most encouraging is that he doesn't give up homers - 0.4 HR/9 in the minors. So far averaging 10.5 K/9 and 4.3 BB/9 in the majors. That isn't bad but it is still too many walks to rely on. Since everything else looks ok though, I think if he's able to improve his walk rate, even just a little bit, he could be at least useful with the potential for a lot more. The problem is last year's 20 games in AAA was the only time he ever did that. I'd fell a little better if he was 21 next year not 24 but he's an ok pick-up, controlled through 2016. Of course relievers are a dime a dozen so you don't necessarily need to deal for them.
Corey Brown is an old 25 (turned it in Novemeber). He was kind of shuffled up the A's minor league system for the sake of doing so until AA where he got better as he got older than the surrounding competition. He takes a lot of pitches, which fits in with Rizzo's philosophy and he has moderate power. The question is whether he can maintain a high enough average in the majors to stick. When I see a guy bouncing around .260-.280 over many years and levels my opinion is probably not. Fitting somewhere between Maxwell and Bernadina on the prospect scale I just don't see the point of this guy. Wait, was he drafted by the Diamondbacks? Nope. Ok still don't get it.
It could turn out better, or another deal could be made, but the way I see it Willingham was dealt for basically organizational depth.