Catcher Wilson Ramos pulls up lame at first base after lacing a single in the fourth inning, his second hit in as many at bats. Ramos was forced to leave the game with an undisclosed injury. (Reed Saxon/AP)

The Washington Nationals’ losses have grown familiar in style, a chain of zeroes and ones, of wasted pitching performances and weak offense. Wednesday night, though, brought cruel and potentially damaging variety. It is one thing to lose a series. It is another to lose a left-handed starting pitcher and a star-crossed catcher.

By the fourth inning of the Nationals’ 3-1 loss to the Los Angeles Dodgers, Ross Detwiler and Wilson Ramos had each left with injuries — Detwiler with back spasms and Ramos with a pulled left hamstring, an injury he already missed two weeks healing once this season. Detwiler may or may not miss his next start. Ramos, Manager Davey Johnson said, will be “down for a while” and likely headed to the 15-day disabled list.

“It’s hard for me,” Ramos said. “I don’t want to be on the DL again. I’m pretty mad right now.”

Led by Craig Stammen’s three scoreless innings, Washington’s bullpen threw to Kurt Suzuki for four scoreless innings. Another meager showing by the Nationals’ lineup made their contribution moot, though, and only worsened the sting of losing Detwiler and Ramos.

The Nationals have not won this season when entering the ninth inning trailing. On this night, they gave themselves a chance — albeit a diminished one after Drew Storen yielded an insurance run to the Dodgers in the eighth. Danny Espinosa snapped an 0-for-16 draught with a leadoff single in the ninth against Dodgers closer Brandon League. As Espinosa stood on first, a walking bruise climbed the dugout steps and stepped into the on-deck circle: Bryce Harper, two nights after his collision with the fence, chin covered with a massive bandage.

The Post Sports Live crew talks about Bryce Harper’s head-on collision with the outfield wall in Dodgers stadium during Monday night’s game. (Post Sports Live)

The drama quickly subsided. After Bernadina dribbled a tapper out to League, Harper chopped a groundout to first base. Denard Span grounded out to shortstop. The Nationals retreated to the cramped Dodger Stadium visitors clubhouse having gone 0 for 9 with runners in scoring position.

The Nationals could have moved into a tie for first place in the National League East after the Atlanta Braves lost in Arizona. Instead, they will head to San Diego, three games into a 10-game West Coast swing, facing another heap of injury concerns.

Ramos has already spent 15 days on the disabled list, followed by third baseman Ryan Zimmerman and, currently, right fielder Jayson Werth, who can come off the DL on Saturday in San Diego. Harper has been out of the lineup two straight games after he smashed into the right field fence, but could return Thursday. The Nationals have not had their full lineup together since the first two weeks of the season, and it has shown.

“It’s frustrating,” Zimmerman said. “Not being able to have your team or your lineup together is never good. . . . I think we have guys that are capable to fill in, and we should still score runs. But guys that are in the starting lineup and playing every day are doing that for a reason. That’s why they’re in there. If you don’t have those guys in there every single day, it definitely makes a difference. Other people have to pick it up. I have to pick it up.”

One night after Clayton Kershaw recorded 26 outs of a shutout, Dodgers right-hander Zack Greinke came off the disabled list and became the latest pitcher to shut them down. Adam LaRoche blasted a solo home run to deep right-center field in the fourth inning. Otherwise, the Nationals mustered nothing. The Nationals entered with a .661 OPS, better only than the horrendous Miami Marlins, and it only got worse.

For one night, the Nationals’ offensive woes were not their biggest problem.

In his first at-bat, Ramos crunched a double off the left field fence and felt a slight aggravation in his left hamstring, which he had strained April 11, causing him to miss 15 days. He didn’t think much of it, though, because his hamstring had not bothered him once since he came off the disabled list in late April.

“I was feeling great every day,” Ramos said. “I can’t believe it right now.”

Ramos lined a single to left off Greinke in the fourth inning. As Ramos stepped out of the batter’s box, he instantly slowed to a near-walk. He hobbled to first base, at which point a trainer and Johnson came out to retrieve him.

Ramos said this hamstring strain felt less severe than the first, and he hoped to stay off the DL. Johnson, though, wanted to ensure Ramos did not pull the hamstring once again. “I think we’re going to have to be a little more cautious,” Johnson said. The “plan,” Johnson said, is for minor league catcher Jhonatan Solano replaced Ramos on the roster and back up Suzuki.

As Ramos walked into the dugout, he slammed his helmet, disgusted at his latest misfortune. Ramos missed the Nationals’ final 130 games in 2012 after he tore the ACL and meniscus in his right knee. Ramos rehabbed from surgery all winter, returned for spring training and earned an opening-day start, only to strain his left hamstring 11 games into the season. Hovering over all of his injuries is Ramos’s most harrowing episode, his two-day kidnapping in his native Venezuela in November 2011.

The Nationals had already dealt with one injury. After he dropped a sacrifice bunt in the top of the third, Detwiler started feeling shooting pain in the right side of his back.

In the bottom of the inning, with a runner on first, Detwiler induced a groundball to first base from Adrian Gonzalez. LaRoche fielded the ball to his right and fired to second to start a potential 3-6-1 double play. But Detwiler never made it to first.

Detwiler caught Ian Desmond’s throw a few steps short, and then bent at the waist, in pain. He stretched his arms over his head and walked gingerly back to the mound. Pitching coach Steve McCatty and head athletic trainer Lee Kuntz and huddled with Detwiler. He remained in the game without even throwing a warm-up pitch.

“I couldn’t get extension or get the ball where I really wanted,” Detwiler said.

Detwiler, who boasts a 2.76 ERA, was clearly not quite right. He seemed to have trouble following through with his pitches, and he missed with curves in the dirt and fastballs high and outside. A.J. Ellis singled and Andre Ethier walked to load the bases. In the bullpen, Stammen scurried to get loose. Scott Van Slyke ripped a line drive to the left side, but Ryan Zimmerman stabbed it to turn a game-breaking hit into an out.

“I felt it before,” Detwiler said. “It didn’t really affect me as much as it did in the third inning. It just sucks you got to make your bullpen wear it like that.”

Zimmerman’s play had saved Detwiler’s pitching line, but the injury had already ended his night. Detwiler felt “not all that great now” after the game, he said. “Hopefully tomorrow morning, I’ll feel a lot better.”

Detwiler’s next scheduled start is Monday in San Francisco. He said he didn’t know whether he will make it or not.

“It’s still the day of my last start,” Detwiler said. “I got to wait to see how I feel tomorrow.”

If the Nationals need a starter to replace Detwiler, they would likely choose between Stammen, left-handed long reliever Zach Duke and veteran right-hander Chris Young, whose results have been disappointing at Class AAA Syracuse. Wednesday night, Young allowed eight earned runs on 11 hits, settling his ERA over five minor league starts at 7.96.

Before the 2010 season, Detwiler underwent surgery to repair torn cartilage in his right hip and missed the first three months of the season. He said that injury was related to the back spasms.

Detwiler left trailing, 2-0, after allowing six hits, including an opposite-field single to Greinke that drove in a run in the second inning. The modest lead served for the Nationals’ offense as a major obstacle: They had not rallied from a deficit of two runs or larger to win all season.

After LaRoche’s homer, which gave him a career-high 12-game hitting streak, the Nationals hardly threatened until the sixth. Suzuki’s two-out single off reliever Matt Guerrier put runners on the corners. The wrong man, at this moment, came up next. Espinosa weakly grounded the first pitch he saw to second base, making him 0 for his last 16.

Their impotence reached a new low in the eighth inning. Steve Lombardozzi and Ryan Zimmerman led off with back-to-back singles off Kenley Jansen, putting runners on the corners with no outs. Their cleanup hitter, LaRoche, stood at the plate, and the tying run stood 90 feet away. Surely, they had found an opportunity they couldn’t waste.

Except they did. LaRoche flied out to left, not quite deep enough to score pinch runner Eury Perez. Jansen struck out Ian Desmond with a high fastball. The inning fell to Suzuki, with two runners in scoring after Zimmerman’s swipe of second. Suzuki lifted a fly ball to right field, and after it settled in Andre Ethier’s glove, both runners skulked off the field.

“We had the right guys up there,” Johnson said. “I don’t know if we’re trying to do too much instead of just hitting the ball. I don’t know. But we’ll figure it out. We’ve got the guys to do it.”

The Nationals have not won when trailing after seven innings all season, and they would have to wait for another chance in San Diego. It did bring another difficult night to swallow, for reasons beyond their ineffective bats.

“Tough night,” Johnson said. “Tough night.”