D.C. United's Wayne Rooney, left, and Luciano Acosta combined for 22 goals this season. (Nick Wass/AP)

Nick DeLeon sat in the Audi Field locker room Thursday night, hunched over in silence. His eyes gazed ahead, locked in on nothing in particular, his hands absentmindedly fumbling over a protein shake.

An hour earlier, the D.C. United veteran had served up an electrifying scene of playoff drama, scoring a game-tying volley deep into extra time of an Eastern Conference knockout match against the Columbus Crew. But that heart-racing moment only lead to heartbreak: With the teams tied 2-2 after 120 minutes, it was DeLeon who skied the decisive shot in the penalty kick tiebreaker as Columbus moved on to the conference semifinals.

After United surged from last pace when Audi Field opened in mid-July to the fourth seed in the East, the back-and-forth match served as a fitting encapsulation of club’s 2018 season — a pulsating showcase for the franchise, extended longer than expected before arriving at an unceremonious end.

“It was a hell of a run,” United coach Ben Olsen said. “Don’t let this spoil what these guys did to set the right tone and foundation for Audi Field and the next generation of D.C. United, and who we are and what we’re about. … They got this city interested again in soccer and our team.”

A sellout crowd of 20,600 took in the first playoff game at Audi Field to watch a team that went 11-2-4 over the second half of the season. The atmosphere remained charged throughout the night, as chants and songs typically isolated to the supporters’ groups instead echoed throughout the new venue.

“At the beginning [of the season] no one really talked about us, and if they did they made jokes,” defender-midfielder Paul Arriola said. “Now there’s a lot of people that are going to be talking about D.C. United in the future.”

Defender Steve Birnbaum added: “We’re getting these fans that wouldn’t have come to games before, and they come to one game and I think they’re hooked.”

Come the 2019 MLS season, which kicks off in March, United will carry renewed expectations. English star Wayne Rooney, whose 12 goals and seven assists in 20 games were enough to land him on the MLS MVP shortlist, will be around for his first full season. While Rooney is 33, attacking partner Luciano Acosta (10 goals and 17 assists) is just 24 years old. Key cogs such as Arriola, Yamil Asad, Russell Canouse and Chris Durkin are also under 25.

For a franchise that saw its fan base dwindle as the years passed by at crumbling RFK Stadium, the 2018 season was always going to be a pivotal point in United’s search for relevance. Moments before the shootout that ended with DeLeon’s misfire, Rooney gathered the squad to make clear that “whatever happens, we can proud of what we’ve achieved.”

“We had no right to make the playoffs,” Rooney said. “To do that, we’ve brought belief back to the fans, we’ve brought belief back to the team — and we have to build on that now.”