The Nationals begin the 67-game final leg of their marathon on Friday, hosting the surging Los Angeles Dodgers as part of a 11-game homestand. They sit six games behind the Atlanta Braves in the National League East and five games behind the Cincinnati Reds for the second wild-card spot. To hit 89 wins, the mark recently needed to make the playoffs, the Nationals need to finish 41-26, a .612 winning percentage.

Entering the second half, here are a handful of the most important story lines to watch in the crucial final two and half months of the Nationals’ season. (Of course, there are more.)

>>> Back end of the rotation: This may be the biggest question mark of the second half. The Nationals are 34-22 in games started by Stephen Strasburg, Gio Gonzalez and Jordan Zimmermann. They are, however, 14-25 in games started by everyone else.

Dan Haren has shown some improvement in his two starts since coming off the disabled list. He attributed the better results to better command (read: keeping the ball down in the strike zone). The Nationals wanted to fully evaluate their $13 million investment once they believed he was healthy and rested. If he repeats what he did last season, in which he posted a 3.58 ERA and 6-5 record after a mid-season stint on the disabled list, the Nationals will be pleased. If not, it — along with Ross Detwiler’s injuries — could force the Nationals to act.

Detwiler has landed on the disabled list twice this season and missed six starts. He started off the season strong (2.76 ERA in eight starts) but he hasn’t been the same since he returned from his first injury, an oblique strain, on June 13 (6.31 ERA in five starts). If his current back injury doesn’t improve enough and his performance continues to be affected by it, the Nationals could have little choice but to acquire starting rotation help. Haren and Detwiler, of course, will take time to evaluate — a delay that could cost the Nationals valuable time to make a move on some of the better starters on the market.

>>> Offense: A lineup that scores 3.76 runs per game (27th in the majors), .has a 241 average (27th), .301 on-base percentage (28th), .385 slugging percentage (24th), .686 OPS (25th) and hit 86 homers (24th) is unsustainable if the Nationals hope to make the playoffs. The offense has also been poor against left-handed pitching (a major league-worst .217) and with runners in scoring position (.243, 23rd in the majors). But, overall, perhaps the biggest issue with the offense is a lack of base runners.

The Nationals will need improvement from their regular hitters. Bryce Harper, who has called his first half “terrible,” has hit .196 with one home run in the 14 games since his return from a knee injury on July 1. Ryan Zimmerman has a .804 OPS, below his .830 career mark and last season’s .824 mark. Denard Span is mired in a season-long slump with his .317 on-base percentage the worst of his career.

There is hope for encouraging trends. Adam LaRoche is traditionally a second-half hitter with a career .845 OPS in July and .911 in August, his highest total of any month of the season. He generally starts slowly and heats up with each subsequent month. Jayson Werth, who has been scorching the ball recently, has been more aggressive and his slugging percentage is at its highest (.466) since his 27-home run season in 2010 in Philadelphia. Also, a healthy, and hot-hitting, Wilson Ramos will continue to help the offense.

>>> Mediocre NL East: Since the Braves began the season 12-1, they’re 42-40. In that span, the Nationals are 40-42 and the Philadelphia Phillies are 42-41. In a division that houses the New York Mets and Miami Marlins, two teams with among the worst records in league, that’s poor. The Braves know they sit atop the division because their hot first two weeks helped mask their woeful inconsistencies and injuries.

The Phillies sit at 48-48, a half-game behind the Nationals, and appear still undecided about their future as buyers or sellers. To drastically improve their playoff odds, the Nationals need at least a hot two weeks, just like the Braves, and could essentially play near-.500 baseball the rest of the way and be in good position to make the playoffs.

>>> Add your own story lines below.


The Nationals are in a hole but are willing to dig out of it.


Nationals’ talks with Osceola County hit a snag

Jordan Zimmermann’s non-existent two-seam fastball


Syracuse 11, Rochester 4: Tanner Roark allowed four runs on five hits over six innings. Xavier Cedeno, Michael Crotta and Erik Davis each tossed scoreless innings. Corey Brown went 2 for 5 with two home runs and three RBI. Will Rhymes drove in one and Danny Espinosa finished 1 for 6.

Harrisburg 12, Akron 3: Nate Karns allowed two runs on three hits, walked three and struck out seven over eight innings. Matt Swynenberg tossed a one-run ninth. Justin Bloxom went 2 for 5 with five RBI, Carlos Rivero finished 3 for 5 with two RBI and Steve Souza Jr. went 4 for 5 with three RBI, finishing a single short of the cycle. Souza, Bloxom and Jimmy Van Ostrand all homered.

Potomac 5, Lynchburg 3: Brian Rauh allowed two runs on five hits over five innings. Richie Mirowski pitched a scoreless ninth to lower his ERA to 1.57. Kevin Keyes finished 1 for 3 with three RBI. Michael Taylor finished 2 for 3 and is now hitting .275.

Hagerstown 15, Hickory 2: Nick Lee allowed one run on two hits over five innings and struck out five. Stephen Perez finished 2 for 5 with a two-run homer. Estarlin Martinez, Wil Piwnica-Worms, Wander Ramos and Tony Renda each drove in two runs.

Tri-City 9, Auburn 3: Casey Selsor allowed five runs, only one earned, on eight hits over three innings. Jake Joyce allowed two runs, one earned, on five hits over 2 2/3 innings. Isaac Ballou, Jean Carlos Valdez and Wilmer Difo each collected two hits.