The Washington Nationals didn't get much production from their non-wunderkind outfielders in 2012, so adding Denard Span and sliding Bryce Harper to right makes the team better by a couple of wins in 2013. The price they paid was heavy, though, with the Minnesota Twins receiving Alex Meyer the kind of hard-throwing, high-upside arm their system lacks.
Span is a solid everyday player who has made himself into an above-average defender in center, a position where his modest bat will play even though he's not particularly patient and has well below-average power. Span's deal pays him a very reasonable $10.25 million total over the next two seasons, with a $9 million option for 2015, so the Nats get three years of control at affordable prices, and can walk away from Span right at the point where he's likely to start to see his value slip. In the interim, however, he gives them an average regular in center whose value will fluctuate with his BABIP.
He has quick wrists and has a handsy swing, putting the ball in play at a very high rate and using the whole field but rarely driving the ball for power. He's a plus runner who gains a few hits each year from his speed and has been worth a few extra runs a year on the bases as well. Yet even in his two highest-BABIP seasons, he's peaked at 4 wins above replacement (per FanGraphs), and the ups and downs of his batting average on balls in play can shave more than a win off that figure. That's still a good fit for a Nats team that lacked a true centerfielder.
For that, however, they gave up a very good pitching prospect in Meyer, who, if he stays healthy, could easily make the Nats regret this deal in the long run. Meyer is generally tabbed as a future reliever because he's primarily a two-pitch guy who, at 6-foot-7, has had trouble keeping his mechanics together, and comes from a slot below three-quarters. I can see all of those concerns and do think there's a chance Meyer ends up in relief, but I'm also somewhat optimistic that he can remain a starter -- and if he does, he'll likely be a very good one, pitching near the top of a rotation.
Meyer has touched 99 and can work at 92-97 even as a starter, with good life on the pitch due to his low slot, although his ground ball rates in pro ball have been just okay. His slider is filthy, a bona fide out pitch whether he starts or closes in the majors, while his changeup has improved to the point where it's probably a future-average pitch. (He hasn't shown any kind of platoon split so far in the minors anyway.) There's a good enough chance that he starts that I'd hate to give him up for three years of a league-average centerfielder unless my club was an immediate contender -- which the Nats are. For the Twins, this gives them the potential frontline starter they didn't see in the 2012 draft class, when they passed on Kevin Gausman and Mark Appel in favor of very high-upside prep center fielder Byron Buxton. Pair Meyer with the resurgent Kyle Gibson, who showed a plus mid-80s slider in the Arizona Fall League, and the Twins' future pitching situation looks a lot more promising.
This does leave Washington's system fairly short on the pitching side at the moment. The Nats' best remaining starting pitching prospect, Luc Giolito, is out until next summer after Tommy John surgery, and while he projects as a potential No. 1 or No. 2 starter, he's probably five years away from major-league impact. Their next-best starter prospect, lefty Sammy Solis, is just coming back from the same operation. Nate Karns is the sleeper, with a plus fastball/curveball combo and a potentially plus changeup, but he's yet to reach Double-A at age 24. They're going to live or die with the pitching already on the big club, or whatever they can add through free agency, because they don't have much arriving soon and their tradeable assets are dwindling.
One other possible beneficiary of this deal is the Colorado Rockies, should they choose to move Dexter Fowler, a talented, athletic center fielder who doesn't have Span's speed or defensive value but has more offensive potential, especially in terms of power. The Rockies' direction isn't entirely clear to me, but Fowler's youth and affordability should net them a higher return than the strong one the Twins just got for Span.