And although United (5-3-2) owns a share of first place in the East through MLS’s first two months, the once-clamorous attack has been reduced to a whimper: five scoreless efforts, six goals in the past seven outings and no second-half goals since March 16.

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D.C. will enter Saturday’s match against the Columbus Crew aiming to end a string of three consecutive scoreless performances at Audi Field — a venue where it scored 21 times in its last nine regular season appearances of 2018 and seven in the first two matches this spring.

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“Hopefully the work we are doing is reflected in the next game,” Acosta said through an interpreter. “We know it needs to get better.”

Much better. Although United has been earning mostly positive results — Sunday’s 1-0 setback at Minnesota was the first away defeat of the year — the attack has labored to rediscover its rhythm and generate opportunities. The defense has faced considerable pressure in recent weeks, barely escaping some tests and breaking in others.

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Soccer is not a numbers game, but some statistics illustrate United’s problems: Three of the past six goals have come off Rooney’s set pieces (two goals and an assist). The other three came in the run of play during an eight-minute burst at Colorado.

All of the scoring in the seven-game span has come before halftime. Opponents, meanwhile, have scored five in the first half and five in the second.

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In that stretch, United has been blanked four times and averaged three shots on target and 4.3 corner kicks.

In addressing the second-half performances and output, Coach Ben Olsen cited injuries and the fatigue from a busy stretch of matches.

But he also said, “Maybe there is an away mentality of bunkering when we need to be a little braver with the ball, both players and coaches tactically in the way we go about the second half of games.”

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On Sunday, after a questionable call nullified defender Donovan Pines’s first-half goal, United did not record a shot on goal in the second half. Less than a month ago, the team failed to test Montreal’s goalkeeper during a 0-0 draw.

Olsen said: “There is some things we have identified that we do in the first halves that we aren’t doing enough in the second halves, whether it’s habits, good shifting defensively, getting better pressure out to the opponent, more running off the ball. Some of that can be fatigue; some of that can also be habits and discipline.”

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Rooney cited “composure” with the ball.

“Second halves of games, even the games we’ve won, we’ve lacked composure,” he said. “Just a bit more composed on the ball will allow us up the field as a team, and we can play in the opponent’s half and create more chances.”

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A big factor in United’s downturn has been injuries. Joseph Mora’s fractured jaw and Chris McCann’s strained hamstring left Olsen without a left-sided defender. To fill the void, he has tried midfielders Paul Arriola, Ulises Segura and Lucas Rodriguez.

None was a perfect fit, and when Arriola and Rodriguez were thrust into that position, United lost key attacking figures.

On the right side, Leonardo Jara missed one game with a shoulder injury and might sit out Saturday with a groin ailment.

Depth at outside back has been a concern since training camp: Oniel Fisher, the starting right back much of 2018, is rehabbing an ACL injury suffered late last season and won’t return for months; Chris Odoi-Atsem is making a comeback from Hodgkin’s lymphoma; and Akeem Ward, a first-round draft pick, is in the developmental stages.

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Help is expected soon as United prepares to finalize a trade with FC Dallas for left back Marquinhos Pedroso. In anticipation of a deal, the Brazilian has arrived in Washington.

Olsen also changed formations in three of the past four matches, using three center backs (instead of two) and starting two wing backs as hybrid defenders with the freedom to go forward. The move was done in part to make the most of Arriola’s and Rodriguez’s attack-minded skills.

However, the adjustment to the new alignment and the loss of Arriola or Rodriguez in an advanced role has damaged the attack. United often finds itself with too many players in deep-lying positions.

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Asked whether the formation has impacted matters, Rooney said: “A little bit. We’ve been forced into it. We’ve had injuries and had players playing out of position.”

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Once Pedroso gets settled, Olsen seems likely to return to the regular formation and leave Arriola and Rodriguez in their common positions.

Without mentioning Pedroso, Olsen said, “We’ll get some reinforcements in here and at some point switch back” into a four-man back line.