Union rookie Jack Elliott showed well in his MLS debut
Saturday, a 2-1 loss to D.C. United. (AP)

With his 6-foot-5 stature, Jack Elliott is used to standing tall. But the rookie’s ability to not shrink from his MLS debut Saturday night at RFK Stadium spoke to more than just his physical mettle.

Elliott took his MLS bow under difficult circumstances, for a Philadelphia Union team trailing two goals at halftime. But he acquitted himself well for a defense that didn’t allow a third goal, giving the team space to attempt a comeback in what went down as a 2-1 loss to D.C. United.

Elliott, drafted in the fourth round of the 2017 MLS SuperDraft out of West Virginia, entered at halftime for Richie Marquez, who suffered an apparent concussion.

“I had to do a job,” Elliott said. “Richie went out at halftime and I stepped up. It felt great to finally be on the pitch for my MLS debut. At the same time, we didn’t come out with the result, so bittersweet.”

Marquez got kicked in the head by goalie Andre Blake in a scramble in the 15th minute. He soldiered on, conceding a penalty in the 26th minute on a handball converted by D.C.’s Luciano Acosta. Manager Jim Curtin said that Marquez felt fine after the initial on-field concussion testing but experienced blurred and double vision later in the half and couldn’t continue.

In stepped Elliott, the 77th pick in January.

“You tell Jack to do what he’s done in training each and every day,” Curtin said. “He’s worked hard to be the reserve center back right now. He stepped in and performed very well. You can see his qualities on the ball. Composed on the ball, and he wins everything in the air. He did a good job in a 45 minutes where we were on the ball a lot, had a lot of the run of play.”

Elliott wasn’t heavily tested, the Union monopolizing possession in search of goals. But the London native handled what limited touches he had well, preventing D.C. from adding to the deficit.

Injuries have aided Elliott’s rise up the depth chart, with Josh Yaro’s long-term shoulder injury and an Achilles strain limiting Ken Tribbett from the start of the season. Tribbett played for Bethlehem Steel Saturday, Elliott preferred to him for a spot on the bench for a third straight week.

The Union certainly have precedent for unheralded defenders earning and keeping spots in the defense. Marquez, a third-round draft pick, did so in his second year after his rookie campaign was spent in Harrisburg, while Tribbett established himself as a regular last year after being signed as a free agent in the offseason.

Elliott has impressed Curtin with his touch at the back, having played in midfield at West Virginia. And the 21-year-old’s poise adds another to the list of positives in his coach’s eyes.

Elliott admitted to some early nerves but quickly settled into the game. Having a veteran central defense partner like Oguchi Onyewu helped, he said.

“I told him, you’ve been here before,” Onyewu said. “You’re not playing basketball. This is what he does, just to enjoy it and play simple. Get the hang of it, play simple, and once you get the rhythm and confidence, you can start trying more daring things. I think he did absolutely fine for his first professional game. He was solid, he was strong, strong in the air, strong in the duels. I congratulated him afterwards.”

“He’s a great guy and fantastic defender,” Elliott said. “It helps as a young guy to have that established center back next to you.”

Elliott followed the same path on the field as to what got him to the bench early in the season.

“I guess I just play my game and whatever comes out, comes out,” he said. “Just try a few things, play simply if that doesn’t work.”