For the first three months of the season, Jordan Zimmermann’s dominance on the mound made him one of the best pitchers in baseball and earned him his first all-star selection. He posted a 2.28 ERA in his first 16 starts, which included three complete games, from the beginning of the season through June.

Slowly, Zimmermann began to tail off. His previous August starts were good, but in his nine starts since July 1, Zimmermann has a 5.96 ERA and has averaged only 5 1/3 innings per start. He walked 17 batters in his first 16 starts, but has walked 16 over his past nine. Opponents are hitting .303 off him, when through the first three months he held them to a .209 average. He has allowed four runs or more in four of these past nine starts, including one of his worst games of the season on Monday, in which he allowed eight runs on seven hits and three homers and two walks.

Zimmermann has said his stiff neck isn’t bothering him and feels fine. He says he and his stuff feel fine. His manager believes the right-hander is throwing the ball well. That is what is making this all of this all the more frustrating.

“I know he feels good,” Manager Davey Johnson said. “He’s not complaining about anything. He feels pretty good. It’s frustrating when you feel good and you’re getting hit. It’s all about making pitches, making pitches to set up pitches. Especially in this ballpark. You make a mistake here, anybody can get it.”

In recent starts, Zimmermann felt like he was rushing his delivery, which was causing him to leave the ball up. That might have been the case on Monday, but it was too soon to tell, he said, without poring over the film of his start. As has been his recent trend, Zimmermann’s pinpoint command has been off. He is leaving too many balls up in the strike zone. He pitches to contact and if he misses high he is more likely to be hit hard and hit out. When he kept the ball down in the zone, he induces quick outs and groundballs.

“My stuff’s been good all year,” he said. “Fastball’s been good, slider was good tonight. Just the location was off [Monday]. Just the location was off [Monday] and something I’ve got to work on.” He added later: “I’m not hitting my spots right now. The fastball’s up. I’ve got to do a better job of locating.”

With a pitch-to-contact starter like Zimmermann, there is bound to be some bad luck and regression. Some advanced statistics earlier in the season suggested Zimmermann’s numbers would even out some. But Zimmermann’s command has been most to blame. He walked two batters before he served up two of his three home runs on Monday.

“I just made a few mistakes tonight and made them at the wrong time,” Zimmermann said. “A hanging curveball and a fastball that was pretty much middle. The two home runs killed me. I can live with the solo home run or even a few base hits, but when you get guys on you’ve got to really buckle down and make some pitches and I wasn’t able to do that.”

Zimmermann has the track record and has been consistent enough throughout hisfive-year career to suggest he will pull out of this recent trend. Johnson believes that he will.

“He’s a tremendous pitcher,” Johnson said. “He’s going to be fine. This was not good, obviously. But I think he came through it alright.”

FROM THE POST

The Nationals are dismantled by the Cubs, 11-1. It wasn’t pretty.

FROM YESTERDAY’S JOURNAL

Osceola County rejects Nationals’ spring training plan

Nationals acquire David DeJesus from Cubs; release Roger Bernadina

The Nationals’ struggles in close and low-scoring games

Bryce Harper’s eventful weekend in Atlanta

NATS MINOR LEAGUES

Syracuse 6, Indianapolis 2: Jeff Mandel allowed one run over seven innings and struck out six. Tyler Robertson tossed a scoreless inning and Ryan Mattheus allowed on run on two hits. Corey Brown went 3 for 4. Will Rhymes finished 2 for 2 with three RBI. Zach Walters drove in two.

Harrisburg was postponed.

Potomac 5, Wilmington 3: Brian Rauh allowed three runs on ten hits over six innings. Travis Henke tossed two scoreless and Colin Bates added a scoreless frame. Brandon Miller went 2 for 4 with two RBI. Michael Taylor went 2 for 3 and Francisco Soriano added two hits.

Asheville 4, Hagerstown 2 (7): Nick Lee allowed four runs, three earned, over four innings. Ronald Pena threw three scoreless. Narciso Mesa went 3 for 4. Shawn Pleffner and Wander Ramos drove in the Suns’ only runs.

Hagerstown 4, Asheville 0 (7): Ian Dickson fired five scoreless innings. Jake Welsh and Gilberto Mendez added scoreless frames. Estarlin Martinez hit a two-run homer. Shawn Pleffner went 2 for 3.

Jamestown 8, Auburn 7: Joel Barrientos coughed up six runs over three innings and Silvio Medina fired four scoreless after him. Jean Carlos Valdez went 3 for 5 with a two-run homer. Matt Foat went 2 for 4 with two RBI. Kyle Att also drove in two.