Outfielder Bryce Harper, who will not be eligible to return from the disabled list until June 11, has a few words for reliever Ian Krol, who allowed one hit while striking out three in his Nationals debut Wednesday. (Jonathan Newton/The Washington Post)

The Washington Nationals had searched all season for a hinge, the victory that would beget more victories, a demarcation between a nightmare start and the moment they wake up. Maybe, they thought, it had arrived Tuesday night. The Nationals had dogpiled in the middle of the diamond for the first time. Manager Davey Johnson shaved his gray scruff, the scraggly goatee he had worn for weeks as a hex breaker. “It’s time to go,” right fielder Jayson Werth said.

Baseball loves its cliches, and maybe the most frequently repeated dictates momentum carries as far as the next day’s starting pitcher. On Wednesday night, in a 10-1 dumpster fire against the New York Mets, the good vibes created the night before evaporated under the unsteady care of Dan Haren. He surrendered three home runs and lasted only four innings, continuing his own rocky season and halting any whiff of a Nationals winning streak.

On the day they placed Stephen Strasburg on the disabled list and made Anthony Rendon their second baseman, the Nationals (29-30) tumbled back below .500 and into third place, passed by the Philadelphia Phillies, who had won in the afternoon. They will wake up Thursday morning a season-high eight games behind the first-place Atlanta Braves — and only 41 / 2 games ahead of the fourth-place Mets.

“We definitely haven’t got going the way we’ve been hoping to get going,” center fielder Denard Span said. “There’s really no explanation for it. We just haven’t played good. I’m going to be honest. Just all across the board.”

Haren earned the brunt of the blame, allowing seven hits and five runs in his four innings. By the end of his short night, he tied for the major league lead in home runs allowed with 15, and his ERA had risen to 5.45. For Haren to match his season ERA with his career ERA entering this year, he would have to throw 331 / 3 consecutive scoreless innings. Some nights he feels encouraged, and Wednesday night he just felt lost.

The Post Sports Live crew debates whether it’s better for the team if injured Nationals play through the pain. (Post Sports Live)

“I have no idea,” Haren said. “It’s not for lack of trying. I’m going out there. I’m doing my best. I feel like I’m letting down the team, fans, front office, everybody. No one feels worse about it than me. But I’ve got to take the ball in five days, and I’ve got to believe because the team needs me. And I know I’m good. I’ve been good at times this year. Just no consistency whatsoever.”

Once Haren exited, the Mets teed off against the Nationals’ newly configured bullpen. They scored two runs off Craig Stammen in the fifth and three more off Erik Davis, making his second career appearance, in the seventh. In between, 22-year-old left-hander Ian Krol made his big league debut with a scoreless, three-strikeout inning.

The seats at Nationals Park began vacating in the seventh after the Nationals’ offense produced another empty performance against an eminently hittable opposing starter. Right-hander Dillon Gee entered with a 5.68 ERA. Span scored on Ian Desmond’s RBI single in the first inning, and afterward they either squandered rallies or failed to start them.

The Nationals totaled 10 hits but went 2 for 13 with runners in scoring positions and left 11 men on base. In 11 of their past 15 games, the Nationals have scored three or fewer runs. In 17 of their 59 games, they have played in binary code — 1 or 0 runs. One night later, Tuesday’s 3-2 thriller blended in with Washington’s season-long offensive rut.

For one night, the offense counted as only the Nationals’ second-most pressing problem. The Nationals signed Haren this past winter for $13 million to bring stability to the back of their starting rotation. He has brought only unpredictability. In some starts he has shined — he allowed two runs in 71 / 3 innings against the mighty Baltimore Orioles his last time out. More often, he has vacillated toward disaster.

“I’ve got to find ways even when I don’t have my best stuff to go out there and compete and keep us in the game because it’s kind of getting out of hand,” Haren said. “If I’m not throwing the ball well, it’s really bad. If I’m throwing the ball well, everything’s fine. But there’s, like, no in-between. There’s nothing really different. I left balls up in the zone. Ball’s right down the middle. They’re professional hitters. That’s what they do.”

Haren’s style has not been defeated. He based his success for years on the simple formula of limiting walks and maximizing strikeouts. He has 5.89 strikeouts for every walk, an excellent ratio that typically would suggest success. But Haren has an obvious problem for which he has not found a solution: When batters make contact, they splatter his pitches.

The Post Sports Live crew looks at the issues plaguing the Washington Nationals, including injuries to Bryce Harper and Stephen Strasburg and the team’s poor defense. (Post Sports Live)

Haren took the mound in the second with a 1-0 lead. The park still buzzed from the ninth inning the night before, and he had a lead to protect after Rendon had adeptly fielded two grounders at his new position.

“Sometimes you get mistakes and they foul it off or they hit it hard right at somebody or they miss them,” catcher Kurt Suzuki said. “It seems like he can’t catch a break.”

Haren allowed a leadoff double to Lucas Duda, which brought RFK-era National Marlon Byrd to the plate. Haren threw a 1-1 splitter that hung over the heart of the plate. Byrd smashed it over the center field fence. The Nationals’ lead had become a fond memory.

“Definitely after last night’s win, we would’ve liked to have come out with a little bit more intensity,” Span said.

The Mets struck again the next inning, again pulverizing Haren’s mistakes. Daniel Murphy ripped a single to center with one out. Haren fed David Wright a first-pitch, 88-mph fastball at the belt. He blasted it into the red seats.

The Nationals trailed, 4-1, and the rest of the third inning only further ensured the bullpen would be depleted. Byrd drilled his second home run of the night, crushing a cutter Haren could not get down in the zone.

By the end of the night, the Nationals — the third-place Nationals — had relearned a hard truth. They do not need turning points or superstitious facial hair. They need runs from their offense and a veteran starter who can keep the ball on the right side of the fence. Momentum is nice, but it is no substitute for sound baseball.