Dusty Baker wasn’t around to see his bullpen collapse in the ninth inning after he was ejected in the sixth for arguing with first base umpire David Rackley. It was his first ejection as Nationals manager. (Katherine Frey/The Washington Post)

Blake Treinen was the first player dressed and at his locker after Thursday afternoon’s latest bullpen meltdown. If he wanted to hide after letting a two-run lead slip away in the ninth inning of a 5-4 loss to the Chicago Cubs, he didn’t. He buttoned up his shirt, pulled on his watch and stood up to answer for it.

“I came in and didn’t do my job,” Treinen said, his words rushed. “I need to be better. It’s getting exhausting, and I’m sure these guys are sick of seeing the same result when I’m out there.”

Shortly before word filtered through the clubhouse that Nationals shortstop Trea Turner had broken his wrist and would be out indefinitely, Treinen hurried through a few more answers.

The Turner news may have offered Treinen some respite as he sat at his locker, looking at his phone as teammates changed and packed and bustled around him. Baseball clubhouses offer nowhere to disappear, and all Treinen could do was sit in plain sight, well aware of what the public thinks of his ability to handle situations like these and of his fellow relievers — well aware that teammates now have had to defend him and the rest of the bullpen after six games in which they led in the ninth inning only to lose.

Trea Turner suffered a non-displaced fracture in his right wrist when he was hit by a pitch. There is no timetable for his return. (Katherine Frey/The Washington Post)

“You always root for your teammates. There’s not a guy in this clubhouse I don’t want to have success,” said Ryan Zimmerman, who drove in the Nationals’ first run. “So yeah, it’s tough.”

For all the external frustration they foster, games like Thursday’s take a human toll, too. Treinen was recovering his form over the past few weeks, so much so that his manager, Dusty Baker, acknowledged that he was regaining his trust in the fallen closer.

But no one will want to hear about that now, and the game affords no time for pity. Treinen fell behind all seven batters he faced in the ninth. In a game in which the controllable must be controlled, Treinen did not seize command.

“A lot of people have the ability to play up here,” Treinen said. “It’s between the ears that keeps people here.”

Part of the trouble was bad luck, something that has plagued Treinen all season. Opponents’ batting average on balls in play against him has been so high (.380) as to suggest he soon would be due for a helpful regression to the mean — just under .300 league-wide in most seasons.

But while bad luck could explain Javier Baez’s single through the wide-open right side, it cannot explain falling behind in counts or the hit-by-pitch that started it all or the line drives from Tommy La Stella and Jon Jay that sealed the loss.

“I came in and didn’t do my job,” Blake Treinen said after the game. (Katherine Frey/The Washington Post)

Treinen simply has not fared well in the ninth inning, allowing a .356 batting average against and pitching to a 7.15 ERA. In the seventh, for reference, opponents are hitting .286, and his ERA is 3.97.

Baker didn’t see the ninth-inning collapse. He had been ejected earlier for arguing a strike three call on Ryan Raburn, one he saw as a foul tip.

“It was a bad call,” Baker said, “and there’s no way I should have been ejected.”

His first ejection as Nationals manager left him to watch in the tunnel beyond the dugout, where he could hear but not see.

“I kept hearing the Chicago Cubs [fans] cheering, so I figured it was something that happened adversely,” Baker said. “. . . It was a bad series of events there in the ninth inning.”

Officially, Chris Speier was the man who chose to bring in Treinen for that ninth inning, the one who pulled Joe Ross after 6 2/3  innings of two-run ball, then chose Matt Grace, Oliver Perez and Joe Blanton to get the Nationals to the ninth with a two-run lead.

That he had to go to Treinen reveals a deeper issue, beyond the agonizing struggles of one reliever. The Nationals’ bullpen simply does not have the depth to withstand multiple close games in a row.

To win the two before Thursday’s, Baker had to use Matt Albers and Enny Romero two days in a row. He used Albers with a five-run lead Wednesday, a decision some questioned, though you can hardly blame Baker for being cautious given what he has seen this season.

So with Albers and Romero out, the Nationals had to piece together the last 2⅓ innings. They could not do it.

“We are a really good team now,” Baker said, “but we still need some help.”

Help would allow Treinen to go into his more natural setup role, the one in which he seemed to find his groove before losing it again. It would allow Romero and Albers to be strong setup options instead of being relied on to finish close games. It would allow Perez to go back to being a veteran matchup lefty.

Help, though it will not come cheap before the Aug. 1 trade deadline, also will alleviate the stress felt by those in the Nationals’ bullpen. And eliminate the need for teammates to tread carefully — or not — when speaking about the most frustrating losses of their season.

“It’s definitely tough to lose some ballgames like that,” Bryce Harper said. “But we just got to keep rolling, hopefully score some more runs. Who knows? Maybe if we scored nine or 10, we might have won that game.”