D.C. United goalkeeper David Ousted jousts with Orlando City’s Justin Meram during season opener Saturday. (Stephen M. Dowell/Orlando Sentinel via AP)

The blame for D.C. United’s failure to win a match in which it held a lead and a man advantage fell on the collective inability to dictate terms and keep possession in the second half. But in the wake of the 1-1 draw at Orlando City on Saturday, there was another serious issue, one that haunted United last year: missed scoring opportunities.

D.C. was very good in the first half, connecting passes, counterattacking and creating danger. Its efforts were rewarded in the 32nd minute when Yamil Asad’s free kick entered a tangled mix of players and exited untouched into the net.

Other chances, however, were wasted, most notably Darren Mattocks’s penalty kick in the 20th minute. Before that, United should have gone ahead 67 seconds into the match: Zoltan Stieber’s high pressure forced a giveaway and Ulises Segura, with a four on two entering the penalty area, took it himself and missed badly from 14 yards.

Segura’s strike from distance in the 50th minute was true, but Joe Bendik made a fine save.

In the 79th, with Orlando committing extra players into the attack, Mattocks embarked on a partial breakaway from just inside midfield. He remained behind the defense as he entered the penalty area but took one too many touches, allowing fast-closing Mohamed El-Munir to disrupt the shot attempt. Orlando had life.

It bears repeating that the Lions were a man down the entire second half — yet dominated possession the final 30 minutes. The hosts kept 56 percent of (non-threatening) possession in the first half and finished with a 59-41 advantage. Given the 11 vs. 10 situation after the break, those numbers were embarrassing for United.

Even with the possession and game-management issues, D.C. created enough quality opportunities to secure three points well before Stefano Pinho scored the stoppage-time equalizer.

Scoring problems are nothing new for Ben Olsen’s squad. Last year, United equaled the MLS record (held by the 2010 D.C. squad) for scoreless performances with 17 empty efforts in 34 matches. The individual top scorers were Luciano Acosta and Patrick Mullins with five apiece. Four of Mullins’s goals came in one half of one late-season game. Next on United’s 2017 scoring chart: own goal (four).

United spent the offseason bulking up the midfield, locating a replacement for goalkeeper Bill Hamid and addressing central defense. As for the goal-scoring role, the club decided against spending top dollar on a proven striker and instead traded for Darren Mattocks, a fast forward whose career high was seven in his 2012 rookie season in Vancouver.

Olsen and General Manager Dave Kasper liked what they saw late last year when Mattocks was thrust into Portland’s starting lineup. In preseason, he scored three times in four matches. If Mattocks falters, United will turn to Mullins, who made a resounding impact upon arriving late in 2016 but struggled with injuries and form last year.

United does not need a 20-goal striker to enjoy a successful season — Olsen has repeatedly emphasized the importance of collective production — but with opportunities at a premium while playing 12 of the first 14 matches on the road, D.C. can’t afford to squander too many of them.

Or, in broader terms, fail to secure three points with a man advantage.

>> Acosta will return from suspension this Sunday at Atlanta, but will he start?

Fitness is an issue after missing a portion of training camp with a concussion and skipping the Orlando opener. Even if Acosta can’t play 90 minutes, Olsen is probably eager to see the Argentine playmaker combining with his skilled countryman, Asad. Last year, Acosta scored in each of the first two meetings against Atlanta and helped set the terms as United won all three matches.

Given the second-half problems in Orlando, he also promises to bolster the possession game.

>> Chris Durkin, an 18-year-old homegrown midfielder, made his regular season career debut Saturday by replacing Asad in the 73rd minute. Durkin was in the news in the days ahead of the opener as well, the subject of transfer speculation to Benfica.

United officials said there are no plans to sell him. They declined to go into specifics about any formal offers, but sources said Benfica, Hannover, Inter Milan and Club America have shown some interest. Because of his age and pro experience, Durkin would end up playing for a junior squad or loaned to a low-level team.

The Richmond area native is highly regarded by United but has a lot of competition for playing time at holding midfield. Junior Moreno and Russell Canouse are ahead of him on the depth chart, though Canouse has been sidelined several weeks with a sprained knee. He has resumed training and could figure into the game-day squad in the coming weeks.

This figures to be Durkin’s first full season in Washington after spending considerable time away the past two years with the U.S. under-17 national team.

So does this mean United would not entertain at any offers for him? No. But it’s going to take a hefty figure to pry him away.

>> For the home opener Sunday — and at least three other times this season — Atlanta will open all of Mercedes-Benz Stadium to spectators.

The downsized capacity for soccer is 42,500, but with upper levels available, the venue can accommodate more than 71,000. Last year, the expansion side set the league attendance record for a stand-alone match by drawing 71,874 at the regular season finale. Overall, Atlanta’s first season average of 48,200 broke Seattle’s league mark.

This will be United’s first visit to Mercedes-Benz Stadium (artificial turf). Last year, D.C.’s only trip to Atlanta was early in the season when the hosts were still playing at Georgia Tech (grass). The other two meetings were at RFK Stadium.

ESPN will carry Sunday’s match, with coverage beginning at 3 p.m. ET.