Series preview: Washington Nationals have underachieved, but don't be fooled

The Pirates kick off a three-game set against the Nationals Friday in Washington. Here's what to expect.

POSITION PLAYERS: .253/.320/.405. 8.5 fWAR, seventh in the National League. Bryce Harper, who's in the midst of history's most predictable breakout season, is hitting a Bondsian .344/.478/.726 and has produced 4.9 fWAR all by himself. (UPDATE: Harper suffered a hamstring injury last night and might not play the series opener.) The rest of the roster isn't keeping pace, and the problem is that the Nationals haven't gotten much of anything from Ryan Zimmerman or Jayson Werth (both of whom are now injured), or from Ian Desmond. Danny Espinosa, Yunel Escobar and Denard Span have contributed, though, and Anthony Rendon is beginning to help now that he's returned from the knee and oblique injuries that delayed the start of his season.

There is, obviously, the core of a good offense here (Harper basically is a good offense all by himself), but Desmond's poor season really hurts -- he's produced at least 4 WAR in all of the previous three seasons, but he's slightly below replacement level this year. I'm sure that's just as painful for Desmond, who's a free agent after the season and who turned down a $107 million extension offer a couple years back.

PITCHING: 3.94 ERA, 3.31 FIP, 3.61 xFIP. 9.6 fWAR, second in the National League. The Nats are reintegrating Doug Fister and Stephen Strasburg back into the rotation after DL stints, but for this weekend, the Pirates will face Joe Ross, Max Scherzer and Gio Gonzalez. Ross, of course, is the unfamiliar one. The Nationals acquired him from the Padres in the Wil Myers trade over the offseason. He got off to a great start in Double-A, and the Nats promoted him because they had a need. He's looked great in two starts, striking out 12 batters and walking only one in 13 innings while racking up ground balls just like his brother, Padres starter Tyson. (The Nats' other acquisition in that trade, Double-A shortstop Trea Turner, is having an excellent year as well. Great deal for Washington.)

Scherzer is, amazingly, in the midst of the best season of his career so far, cutting his walk rate almost in half compared to his last three years in Detroit -- which, as you might have heard, were pretty darn good. Gonzalez has a 4.82 ERA, but his underlying numbers suggest he hasn't declined much -- his peripherals are still solid, with a few more walks but also a bunch more ground balls.

The Nats' bullpen isn't a strength. Closer Drew Storen is in the midst of a terrific year, but the Nationals have lost Craig Stammen and Aaron Barrett to injury, and their starters haven't worked as deep into games as they'd like. The Nats also don't want to lean too heavily on veterans like Casey Janssen and Matt Thornton. The team recently acquired David Carpenter from the Yankees, and will likely acquire another reliever or two before the trade deadline. The bullpen's unknown, hard-throwing, high-performing youngster (everybody's got one) is lefty Felipe Rivero, who's struck out 10 batters in his first seven big-league innings.

OUTLOOK: Unlike a lot of the jokers the Pirates have played recently, this is a strong team, despite its pedestrian 34-33 record. Harper and the Nationals' starting pitching are so good that they should be able to paper over any weaknesses they might have at the trade deadline, and there are enough talented players who haven't done much of anything yet (including Strasburg, Desmond, Rendon, Fister, well regarded youngsters Michael Taylor and A.J. Cole, and Werth, although it might take Werth a couple more months to get healthy) that they're likely to get a lot of improvement from within. The Nationals' bullpen can use some work, and their team defense isn't a strength, but they'll likely be fine, and they're still easily the favorites to win the NL East.