Chris Pontius of United controls the ball against Vurnon Anita. (Ned Dishman/Getty Images)

D.C. United’s friendlies against esteemed international guests are always difficult to gauge. The visitors set a casual bearing. Substitutions are unlimited. Biting tackles are saved for another day. The outcome is hardly paramount.

And while United was disappointed about conceding a late goal in a 2-1 loss to Dutch titan Ajax on Sunday before 10,728 at RFK Stadium, the young MLS club drew strength from the overall performance.

“These exercises are always interesting — what you can get out of them,” Coach Ben Olsen said. “I thought it was a good day for us.”

After chasing Ajax’s shadows for 15 minutes and yielding Miralem Sulejmani’s early strike, United enjoyed the majority of possession in the second half and drew even on rookie forward Blake Brettschneider’s first goal in a competitive match.

However, just as the long European season, overseas travel and warm weather seemed to sap Ajax’s appetite for victory, Vurnon Anita veered into the clear and scored on a 14-yard effort in the 87th minute.

The four-time European champions, who arrived here for a working vacation after winning a 30th Dutch title, made their first appearance in Washington since a 1990 friendly against the U.S. national team.

The lineup included four starters and three players who entered in the second half of last Sunday’s 3-1 victory over Twente in Amsterdam. Five starters from that decisive match entered after intermission against United.

Over the years, United had fared well in these friendlies, defeating Celtic, Tottenham Hotspur and AC Milan, tying Boca Juniors and Real Madrid (in the first of two meetings), and losing by a goal to Chelsea.

Granted, the opponents arrive when their leagues are dormant and they don’t play at full throttle. But United, almost one-third into the MLS regular season, carries concerns of its own.

With treacherous MLS trips to expansion Portland (5-0-0 at home) and Los Angeles (3-0-2) approaching, Olsen was careful to not overextend his regulars and made seven substitutions.

Starting forwards Charlie Davies (hamstring) and Josh Wolff (groin) were not in uniform, and goalkeeper Bill Hamid, defender Dejan Jakovic and midfielder Dax McCarty left at halftime. Others departed later.

Davies, who seems unlikely to return until the Galaxy match June 3, joined the Screaming Eagles and Barra Brava supporters groups in the second half for song and drum sessions.

Rookie Perry Kitchen, who has started at center back and right back in league play, made an assertive debut in the heart of midfield.

Ajax went ahead in the 10th minute, when sloppy defending allowed Nicolas Lodeiro to link with Sulejmani for an angled one-timer from 10 yards past Hamid. It was all too easy.

“We didn’t touch the ball for about 15 minutes,” Olsen said. “They are an unbelievable team, the way they play. It’s nice to play against a team like that. But after about 15 minutes, we started to figure it out, the game changed and it could’ve gone either way.”

United responded well. Brandon Barklage’s 30-yard drive tested goalkeeper Kenneth Vermeer, two dangerous balls were cleared from the box and the midfield knocked the ball around effectively.

United was a consistent threat throughout the second half. In the 58th minute, Joseph Ngwenya stripped the ball from Anita in the box and crossed to Brettschneider for the simple finish.

“Joe probably deserves the majority of the credit,” Brettschneider said. For his first goal to come against a prestigious foe, “I’ll have that for the rest of my life. I was just happy to be part of this game.”

In the 75th minute, United backup keeper Steve Cronin made a terrific save on Lorenzo Ebecilio. But against the run of play, Anita beat Cronin to the far corner and United squandered a late threat.

“It was a good experience,” McCarty said. “We had a big problem figuring out their possession game at the beginning, but we settled down and played fairly well for 60 or 70 minutes. We had enough chances to say we could’ve walked out with a win.”