Jose Lobaton talks to Nationals starter Max Scherzer during the second inning Friday night. (Eric Risberg/Associated Press)

Seven weeks remain in the Washington Nationals’ season. But Friday felt like the gut-wrenching nadir. Even their best pitcher, Max Scherzer, couldn’t stop the slide. In fact, his recent struggles dug the Nationals into a five-run deficit to the San Francisco Giants. Even their best player, Bryce Harper, couldn’t save the day. His three-run blast trimmed nearly erased Scherzer’s mistakes, but the Giants tacked on two late runs in the Nationals’ 8-5 loss.

The Nationals, in their current state, look little like a playoff aspirant. They are 10-18 since the all-star break. Friday’s defeat was their fourth straight. Their National League East deficit remained at 4 1/2 games because the New York Mets also lost. But the most concerning question about the Nationals is when will this slow bleed stop?

“There are 40-some games left,” second baseman Danny Espinosa said. “We have to win. We can’t let this slip any further. We’ve been on a tough little stretch. Now it’s time to turn it around and win ballgames.”

Sluggish much of the second half, the offense came to life, but the pitching sagged. When one unit of the team is clicking, the other isn’t. Friday’s loss, in some ways, felt like the season all in one night: some excitement sandwiched around disappointment.

“Everybody is fully aware of [our record] that sits in that clubhouse,” Manager Matt Williams said. “We have to prepare for tomorrow. It’s never going to be easy during any game. So one swing of the bat and we might just win that one tomorrow and you never know what can happen from there.”

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All that could go wrong for the Nationals in the first four innings did, and it was miserable to watch. With only one run in 28 innings entering Friday’s game, Williams tweaked the lineup. He sat struggling Jayson Werth, Anthony Rendon and Wilson Ramos in favor of Espinosa, Clint Robinson and Jose Lobaton. And Williams wanted to will the Nationals to score so the team turned aggressive. They turned a walk, stolen base and two outs into a 1-0 lead.

Then the Nationals descended into what felt like a never-ending spiral. Scherzer gave up two hits, including a solo home run to Matt Duffy. His command wasn’t sharp, and his pitches didn’t move as well as usual. The Giants then started smashing his offerings.

The third inning was the hardest for the Nationals to stomach. Scherzer gave up four runs on four doubles and hit a batter. Even though two doubles landed just fair down the right field line, Scherzer wasn’t fooling the Giants. After Gregor Blanco’s two-run double landed no more than two inches fair and gave the Giants a 4-1 lead, Scherzer flung back his head in disappointment.

Scherzer finished the inning, with his pitch count at 49, the Nationals trailing 5-1 and Doug Fister warming in the bullpen. And despite an extra reliever in the bullpen, Williams let Scherzer bat for himself in the third inning and take the mound in the bottom of the frame. Before Scherzer’s night was done and replaced by Fister, he gave up a solo home run to Hunter Pence that sunk the Nationals into a 6-1 deficit.

“We’ve got to try to get innings,” Williams said. “We can’t run through everybody in the bullpen.”

Over his past eight starts, Scherzer has a 5.05 ERA and has allowed 11 home runs. In the clubhouse, Scherzer pored over film of his mechanics and found he was dropping his arm, causing his pitches, especially his fastball, to flatten out.

“It’s a bad time of the year to have a mechanical thing go wrong,” he said. “But I actually think I can fix this within five days.”

The Nationals' acquisition of pitcher Jonathan Papelbon pushed Drew Storen out of the closer role, but will it disrupt the clubhouse chemistry? (Post Sports Live/The Washington Post)

Once the Nationals hit the bottom, the dugout staring blankly at the action in the field, they began to pull themselves out of their hole. In their four-run fifth inning, they took advantage of Giants starter Matt Cain’s wildness. Espinosa homered, Lobaton doubled and Fister singled. With two outs, Harper launched a towering shot into the right field seats to pull the Nationals within a run. Boisterous AT&T Park grew quieter, and the Nationals’ dugout erupted at Harper’s 30th home run of the season.

“I wasn’t sure if they were going to pitch to me or not,” Harper said. “I didn’t know if they were going to do an intentional unintentional walk or something like that. I was ready for something over the plate and he gave it to me and I was able to put a good swing on it and get it out of the yard. Coming within one, I thought we had a good opportunity to win that ball game. It just didn’t roll that way.”

A one-run deficit in the fifth inning is a manageable game. But again, the Nationals’ little mistakes proved their downfall. Once Fister gave the Nationals two scoreless innings of relief, Williams turned to reliever Matt Thornton. He up a double to left-handed Blanco, who stole third. He then walked Duffy on four pitches. Thornton got Brandon Belt to hit a sharp grounder to Ryan Zimmerman, who touched first base and threw home. With an athletic head-first slide, Blanco’s hand snuck in before Lobaton’s swipe tag.

The Giants took a 7-5 lead and then added another run in eighth inning off Jonathan Papelbon. But before that, the Nationals had one final crack at a comeback. After two Giants’ errors put runners on the corner with two outs. Rendon came up to pinch-hit against Giants reliever Sergio Romo. He struck out on four sliders. Despite all their talent, the Nationals moved one loss away from dropping to .500 in mid-August.

“Talk to me in September,” Scherzer said. “It’s still August. What’s the worst-case scenario right now? We can make this up in a week. We’ve just got to play good baseball. That’s all that matters.”