WASHINGTON — Everything seemed to be going in the Braves’ favor when they notched an improbable comeback win on Friday night and began Saturday’s doubleheader with a win.

But by the time this weekend’s four-game series against the Nationals concluded, they had made no progress in the standings.

With Jair Jurrjens enduring yet another rough start, the Braves suffered a 9-2 loss to the first-place Nationals on Sunday afternoon and had to settle for a split in the four-game series.

The Braves are 3½ games out of first place — which is exactly where they were when they arrived in Washington.

As for Jurrjens, he provided the Braves more reason to add a starting pitcher before the July 31 Trade Deadline.

He also created reason to doubt whether he will ever make another start for Atlanta.

“Like I said a week or 10 days ago, we’ve struggled with our consistency because we’ve struggled at the end of our rotation, and we saw it today,” Braves third baseman Chipper Jones said.

“It’s a little demoralizing when you’re in a dogfight for your division and you’re constantly fighting from behind.”

After winning the first two games of this four-game set, the Braves were outscored 14-4 while losing the final two.

If they’re going to vault closer to the top of the division, they will likely need to improve a starting rotation that has posted a 6.62 ERA since the All-Star break.

“They’ve really been playing well,” Nationals manager Davey Johnson said.

“I think they had a seven-game winning streak that was just stopped. They had been playing the best in the division. To win the first two and then get a split out of here, if I were them, I’d feel deflated. You want to pick up some ground when you’re playing well. They swung the bats really good this series, but so did we. We actually should’ve taken three out of four.”

One year after he was a candidate to start the All-Star Game, Jurrjens finds himself as the weakest link in the Atlanta rotation.

The 26-year-old right-hander surrendered two home runs to Ryan Zimmerman and was charged with six earned runs in just 2 1/3 innings against the Nationals.

“He got ahead of the hitters,” Braves manager Fredi Gonzalez said. “I think a couple of the at-bats, he was (ahead) and he just couldn’t get his breaking ball to do what he wanted it to do.”

In other words, this was simply a continuation of the struggles Jurrjens has endured dating back to when he was demoted to Triple-A Gwinnett in late April.

When he returned to the Majors on June 22, he produced some false hope by limiting the Red Sox to one run in 7 2/3 innings.

Two more decent starts would follow. But in two starts since the break, he has allowed 14 earned runs and totaled just 5 2/3 innings.

“That’s just two bad starts,” Jurrjens said. “I know it’s really two ugly ones, but ever since I came up I’ve been dependable. Hopefully they give me a chance to prove myself again.”

Jurrjens’ plea to remain in the rotation is weakened by the 7.04 ERA that he has compiled in 10 starts this year and the 6.50 ERA he has compiled in 17 starts since pitching in the 2011 All-Star Game.

Still, less than 15 minutes after his team had concluded a key series in tough fashion, Gonzalez was not ready to reveal whether Jurrjens would make another start.

The Braves can go with four starters until July 31.

Instead of going with Jurrjens that day, it seems more likely that they would give the start to Randall Delgado or one of the starting pitchers they are hoping to acquire via a trade.

“We’ve got time to talk about that,” Gonzalez said. “I have not even thought about that right now.”

Jurrjens surrendered hits to nine of the 15 batters he faced on Sunday and exited in the third inning with the Nationals leading, 6-0.

Unfortunately for the Braves, they were unable to match the comeback victory they produced after carrying a nine-run deficit into the sixth inning of Friday night’s series opener.

The only two runs the Braves generated against Nationals starter Ross Detwiler on Sunday came after Martin Prado singled to start the sixth inning and Jason Heyward followed with a double.

Prado also notched one of the three singles that helped Atlanta load the bases before Brian McCann grounded into a double play to end the top of the fourth inning. It proved to be a key play in the game.

“That kind of took the steam out of it,” Gonzalez said of the fourth inning.

“You feel like in the course of a game like that, there is going to be an opportunity where your team gets back in it somehow. That was our opportunity and we didn’t take advantage of it. Detwiler settled down a little bit and the rest is history.”

Zimmerman got the Nationals rolling with a two-run homer in a four-run first inning that also included a Danny Espinosa double.

After getting through the second inning unscathed, Jurrjens began the third inning by surrendering Zimmerman’s second home run and a Michael Morse double.

Two batters later, Espinosa ended Jurrjens’ outing with an RBI single.

This marked the first time since joining the Braves in 2008 that the veteran pitcher completed fewer than three innings when not influenced by injury or weather-related issues.

“Our chance to win the series was last night and we didn’t get it done,” Jones said.

“Today was not good from pitch one. But we came in here, held our own and I thought we played well for the most part. We’re right back to where we started.”

The Braves travel to Miami tonight to open a series against the Marlins.