Roger Bernadina, who had one of Washington’s three hits, exits the dugout after the Nationals’ third loss in four games with the Orioles. (Jonathan Newton/THE WASHINGTON POST)

The Washington Nationals have completed the first third of this season — one given a “World Series or bust” slogan by their manager this winter — and they are a .500 baseball team. After Thursday’s 2-0 loss to the Baltimore Orioles at Camden Yards, the offense remains dormant, the pitching about as strong as expected, and the record a dead-even 27-27. An important series in Atlanta against the division-leading Braves looms this weekend and the pressure on the club is starting to build.

After signs of an offensive awakening the past four games, the Nationals were stifled by 36-year-old journeyman Freddy Garcia and his split-finger fastball for eight innings, getting shut out for the seventh time. Dan Haren provided a valiant effort over 71 / 3 innings against a treacherous lineup but was doomed by a handful of mistakes and no run support.

The Nationals walked off the field here a .500 team with June a day away, an unexpected reality. Nationals Manager Davey Johnson was perhaps the tersest he has been following a game all season, speaking with reporters for 90 seconds, with the loss clearly wearing on him.

“We need to get some guys back that are hurt and some of the young guys are struggling,” Johnson said, without elaborating, when asked if the team needed changes. “We’ll probably make some changes. But that’s for another day.”

The Nationals have dug themselves a hole. If they hope to reach 90 wins, the victory threshold that historically makes a playoff spot in the wild-card format close to a sure bet, they will have to go 63-45 the rest of the way — a .583 winning percentage. One prolonged hot stretch could get them to that mark, but the only thing this team has been able to prolong thus far is its own inconsistency.

The Post Sports Live crew discusses what would happen to the Nationals’ lineup if Bryce Harper keeps suffering minor injuries. (Post Sports Live)

“I wish we could go 7-3 every 10 games,” third baseman Ryan Zimmerman said. “Unfortunately it hasn’t worked out so far. We just gotta keep grinding and keep working and keep getting better and hopefully in September we’re going to be where we want to be.”

Their record has sat at .500 seven times, a mark they hit only once during their magical 98-win season of 2012. The offense continues to be the biggest weakness, but flaws also appeared in the bullpen and defense early on as well. Injuries, too, have sent five key players to the disabled list and held their best player, Bryce Harper, out since Sunday. Their fortunes can change — but now frustration occupies that space.

“It’s no more complacency,” shortstop Ian Desmond said. “It’s time to turn it on. Sometimes a little adversity like this can break teams apart. We’re going to stick together. As a team we’re going to figure it out.”

On Thursday, the conditions were similar to the previous game’s offensive shootout. The Haren-Garcia matchup had the makings of a hitters’ delight. Haren entered with a 5.63 ERA and Garcia, in his sixth start with the Orioles, with a 4.61 ERA. Both pitchers had the propensity to allow home runs. Instead, baseball again proved it could not be predicted.

Both starters pitched into the eighth inning. The Orioles made a lot of loud outs against Haren in the early innings but he settled into a groove. He allowed a run in the third inning when, with a runner on base and two outs, he gave up a single to Manny Machado and then a run-scoring double to Nick Markakis.

The Orioles chased Haren in the eighth, after 105 pitches, following a leadoff double to Nate McLouth and then a run-scoring double to Machado. After a defensive lapse by Danny Espinosa and Roger Bernadina in right field while Fernando Abad was pitching, Espinosa turned a double play induced by Drew Storen to end the inning. The Nationals trailed 2-0 after eight, a deficit hard to overcome with a struggling offense.

“We really needed a win [Thursday],” Haren said. “It was a tough one [Wednesday] and I was determined to win this game.”

The Post Sports Live crew debates which injured player’s return would be the biggest help to the Washington Nationals’ struggling offense. (Post Sports Live)

Garcia, released by the San Diego Padres near the end of spring training, took advantage of an over-eager Nationals lineup, allowing just three hits and striking out six over eight scoreless innings. Garcia entered the game with only nine strikeouts. The Nationals flailed at Garcia’s frequent offering of a split-finger. It was not the first time the anemic offense was at the heart of a Nationals loss.

“He just didn’t make many mistakes tonight,” Espinosa said of Garcia.

Unlike last season, some starters and fill-ins for injured starters have struggled. Chad Tracy (.160), Tyler Moore (.144) and Bernadina (.154) — key bench players during injuries — have yet to get on track. Second baseman Espinosa, in his second game back from resting a fractured right wrist, saw a total of two pitches in his first two at-bats. Four of the nine hitters in Thursday’s lineup were hitting under .200. Before Bernadina singled in the top of the sixth inning with two outs, Garcia retired 14 Nationals hitters in a row.

“We just haven’t all hit our stride at the same time,” Espinosa said.

“It’s just a little inexperience,” Johnson added. “We’re trying to make something happen and expand the zone. Got to get strikes.”

Injuries have also depleted these Nationals. Harper, their best hitter, hasn’t played since Sunday with an aggravated knee injury. The Nationals are 2-9 without him, his bat and defense are missed, and he could return on Friday. Starter Ross Detwiler and reliever Ryan Mattheus are also on the disabled list. Jayson Werth has been out since early May with a strained hamstring. Wilson Ramos is also out with a re-strained hamstring. The remaining hitters and bench players haven’t been able to pick up enough slack.

Now the Nationals travel to Atlanta for a key series having lost three of four to their regional rivals and in dire need of a hot stretch. Haren was on the 2012 Los Angeles Angels of Anaheim, a team with high expectations that floundered, and insisted that this season’s Nationals are different. Their deficit is manageable. They trail the Braves by 51 / 2 games entering the weekend series.

“We go there and win some games and we’ll feel real good coming home,” Haren said. “I don’t think it’s a situation where we need to panic, everyone knows we just need to play better. We have the talent. We’re a little banged up but everyone knows we have to play better.”