Washington Nationals Juan Soto, left, and Anthony Rendon celebrate after scoring on a single by Daniel Murphy during the seventh inning Sunday at Citi Field. (Seth Wenig/Associated Press)

The last time the Washington Nationals dispersed for the all-star break with a record at .500 was 2011. This organization had never made the playoffs then, never had to deal with pressure. The team was not capable of disappointing then, not like it is now — not like it has in this first half of the season, which ended with a 6-1 win over the New York Mets on Sunday at Citi Field. The Nationals are 48-48. The 48th win was one of the few simple, pleasant afternoons they have had all year.

So much has changed in those seven years. A first half like this one, riddled with injuries that do not fully explain the inconsistency, now qualifies as unacceptable. This organization fired its previous manager because two division titles and two 95-plus-win seasons in two years were not enough. This team will have to go 47-19 in the second half to win that many games and make up 5 1 /2 games in the standings to earn a third straight division title.

“We all will agree we haven’t played our best baseball, even over a week or two stretch,” said Trea Turner, who singled home two runs in a five-run seventh. “. . . But the time is now. We’ve got to perform and get those wins in the second half.”

Jeremy Hellickson (4-1) started Sunday’s game and threw six innings of one-run ball, allowing a run or fewer for the seventh time in 13 starts. This rotation fell apart when injuries to Hellickson and Stephen Strasburg left the team scrambling for backup and when Tanner Roark and Gio Gonzalez began to struggle simultaneously.

Roark and Gonzalez showed signs of stabilizing this week, and Strasburg threw 82 pitches in a rehab start Sunday and should return for the second-half opener against the Atlanta Braves. The Nationals plan to open the second half with their expected rotation fully intact for the first time since early June. When it was intact, this team compiled its best month of the season, a 20-7 record in May.

“We’re going to need everybody,” Hellickson said. “Philly and Atlanta aren’t going anywhere. We’re going to need everybody to step up and just play how we’re capable of playing.”

Bryce Harper rested for Sunday’s series finale, which was Manager Dave Martinez’s way of compensating him for the days of rest he’ll lose to the Home Run Derby and All-Star Game this week at Nationals Park. Harper was conspicuous in his relative absence, a phrase that sums up the first half of his free agent year.

Harper hit 23 homers and drove in 54 runs, power numbers as good or better than those he has accumulated in his best seasons. But he also batted .214, .233 with runners in scoring position, which is well below his career norms.

Harper becomes the focus of most conversations about this lineup, but that it scored one run in five innings against rookie right-hander Corey Oswalt on Sunday was not his fault. That run came when Michael A. Taylor grounded into a forceout that brought home Anthony Rendon in the second.

Small ball, moving runners, manufacturing runs — these are all things Martinez says his team must do more. His players bring them up, too. Last year, the Nationals led the majors with an .837 on-base-plus-slugging percentage with runners on base. This season, they are at .757 — good for 13th — largely with the same player personnel.

“People can say look at our record, the Nationals should be this, that, but I’m proud of the boys and this team,” said Martinez, who was bench coach for the Chicago Cubs when they turned a 5½ game deficit and sub-.500 record at the break into a division title last season. “We went through some adversity. . . . I credit these guys for being where we’re at right now, and we’ve still got a lot of baseball left.”

Coaching cause and effect is complicated, tough for even players to discern. Because of all the injuries, correlation is even more complicated with this team. But the Nationals’ rookie manager has already had to answer questions about his impact on this team, though his most discussed decisions of the first half dealt predominantly with the pitching staff.

By the top of the sixth Sunday, Martinez faced a decision he has encountered repeatedly this season. His team was in a close game, in need of offense. His starter was due up. As he has done often with starters other than Hellickson, he let his pitcher hit for himself, despite having a full bullpen at the ready with four days of rest upcoming.

At times, those choices have backfired, with the pitcher making an out then struggling to get through one more inning. In this case, Hellickson singled, then threw a scoreless sixth to validate the move. An inning later, the Nationals loaded the bases with no one out for Taylor, and Martinez pinch-hit Daniel Murphy.

Murphy singled home the go-ahead runs to start a five-run outburst, delivering the kind of hit that has not come often enough for this team — the kind of hit he was not healthy enough to provide until a few weeks ago.

“Each team going into the end of the first half sees opportunities that they missed and areas where they played really well,” Murphy said. “. . . But I think the biggest thing is you take a step back, take a breath, so that when we come back we finish the second half sprinting through the finish line.”

Whatever happens next, this team is aware that what has happened so far is not nearly good enough — or so many of its players say. This is far from over, but the Nationals can no longer plan for a leisurely climb. Only 66 games remain.