Manager: Kirk Gibson, fifth year
Last 10 games: 4-6
Who to watch: C Miguel Montero (.256/.339/.401, 20 doubles, 12 HR, 63 RBIs); 2B Aaron Hill (.245/.284/.376, 22 doubles, 10 HR, 55 RBIs); RHP Chase Anderson (7-4, 3.16 ERA, 1.30 WHIP); LHP Vidal Nuno (0-3, 3.92 ERA, 1.13 WHIP)
Season series vs. Nats: 1-2, 9 runs scored, 12 runs allowed
Aug. 18: Vidal Nuno vs. Jordan Zimmermann, 7 p.m., MASN HD
Aug. 19: Chase Anderson vs. Stephen Strasburg, 7 p.m., MASN HD
Aug. 20: Trevor Cahill vs. Tanner Roark, 7 p.m., MASN HD
Aug. 21: Wade Miley vs. Gio Gonzalez, 4 p.m., MASN HD
The Diamondbacks' season can be separated into three parts - the atrocious start, the righting of the ship and then, well, August.
Arizona began its season in awful fashion, going 8-22 out of the gate. But the club played pretty much .500 ball from there, going 40-39 over its next 79 games through July 31.
Well out of the playoff hunt, the Diamondbacks moved super utility man Martin Prado, outfielder Gerardo Parra and starter Brandon McCarthy before the non-waiver trade deadline. Then on Aug. 1, they lost star first baseman Paul Goldschmidt for the season because of a broken hand suffered when he was hit by a pitch against the Pirates.
Arizona is 5-10 this month, a tumble which started the day Goldschmidt was hurt.
The Diamondbacks might be depleted and diminished, but they arrive at Nationals Park hoping to regain the form that had them playing solid ball for nearly half of the season.
Even without Goldschmidt, Prado and Parra, Arizona still ranks in the middle of the National League pack offensively. The Diamondbacks are seventh in the NL with 490 runs and a .692 OPS, 11th with 97 homers and fifth with a .252 average.
Catcher Miguel Montero is Arizona's top healthy bat with a .740 OPS. He ranks in the team's top three with 20 doubles, 12 homers and 63 RBIs.
Second baseman Aaron Hill has contributed 22 doubles, 10 homers and 55 RBIs, but couples that with a .245 average and .660 OPS.
Left fielder Mark Trumbo has been perhaps the team's hottest hitter, batting .370/.439/.522 with five extra-base hits and 13 RBIs in his last 13 games. That has lifted his season average from .196 to .238.
Rookie center fielder Ender Inciarte has also been a positive as he looks to extend the longest active hitting streak in the majors. Inciarte, the Diamondbacks' leadoff man, has hits in 17 straight games to set the club's rookie record. During that run, he's batting .320.
The D-backs lineup has contributed to the recent losing ways, however, as the team has scored more than four runs just twice in 15 games this month and hasn't done so in its last seven contests.
Arizona's pitching hasn't helped much, as the team has allowed at least five runs seven times this month.
But the Diamondbacks have had problems on the mound all season. They rank 14th in the NL with a 4.27 team ERA and 4.50 starters' ERA, and 12th with a 3.84 bullpen ERA.
Arizona has had 11 different pitchers make a start this season. Left-hander Vidal Nuno and right-hander Chase Anderson lead the current rotation, and will start the first two games of the series that features four starters performing well.
Nuno, 26, has pitched to a 3.92 ERA in seven starts since being acquired from the Yankees for McCarthy, but is 0-3 and the D-backs have lost all seven times he's pitched. Nuno is 2-8 with a 4.92 ERA in 24 games (21 starts) overall this season. He faces Jordan Zimmermann in tonight's series opener.
Anderson has been Arizona's best starter since joining the rotation in May. The 26-year-old rookie is 7-4 with a 3.16 ERA in 15 starts. He has allowed more than three runs in a start only twice and hasn't permitted more than four since his second start.
Anderson has put together a streak of six straight quality starts, during which he's 2-0 with a 2.19 ERA, holding opponents to nine runs in 37 innings. He'll go head-to-head with Stephen Strasburg on Tuesday.
Right-hander Trevor Cahill goes up against Tanner Roark in the third game of the series. Cahill (3-8, 4.68 ERA), a former All-Star with the Athletics, is having his most trying season. He lost his spot in the rotation in April after posting a 9.17 ERA in his first four starts. Solid work in the bullpen helped return him to a starting role in mid-July.
Cahill is 2-2 with a 3.53 ERA in six starts since rejoining the rotation. He's been better of late with four straight quality starts, and a 2.18 ERA in his last three outings.
Left-hander Wade Miley faces Gio Gonzalez in Thursday's series finale. Miley is another former All-Star having his worst season, going 7-9 with a 4.46 ERA in 26 starts.
The 27-year-old has performed well since allowing a career-worst 10 runs in 4 2/3 innings on Aug. 5 against the Royals. He has allowed four runs with 17 strikeouts in 13 innings (2.77 ERA) over his last two starts.
On the surface, this series might look like an easy opportunity for the Nationals to extend their NL East lead. But even though the D-backs have struggled all month, all four starters they throw at the Nats have been doing well of late. And the offense has some hot bats to boot. So it might not be as much of a mismatch as it seems.