Milwaukee’s Christian Yelich, front right, circles the bases after hitting a grand slam off Washington reliever Tim Colins, middle, in the fifth inning. (John McDonnell/The Washington Post)

If there was to be a last-ditch run at the playoffs — or even the faintest hint of one — the Washington Nationals had a chance to start this weekend, with three games against the visiting Milwaukee Brewers.

But that chance was buried by Sunday afternoon, by Christian Yelich’s bat, by a home run swing that cleared the bases and put the Nationals in yet another hole. Yelich’s grand slam, off reliever Tim Collins, was the punctuation mark of a seven-run fifth inning for Milwaukee, which roughed up Washington starter Jefry Rodriguez in a 9-4 victory at Nationals Park.

At the start of the weekend, the Nationals trailed the Brewers by 7½ games in the race for the National League’s second wild-card spot. A sweep could have nudged Washington out of free fall and onto the fringe of the postseason conversation. But Milwaukee (77-61), after taking two of three in the series, has not moved from that spot. The Nationals (68-69) have only gotten further away from it, and they are no closer to the top of the NL East with 25 games to play.

“You never give in to the game,” Nationals second baseman Wilmer Difo said. “Today, it didn’t happen for us, but it wasn’t because we changed our mind-set or approach at all. It’s not always going to happen.”

This September, with Washington nearing mathematical elimination, with logic creeping up on hope, young players have a chance to show they can help the organization in the future or the trade market. At the plate, those players are Difo, outfielder Andrew Stevenson and catcher Pedro Severino. In the bullpen, they are Jimmy Cordero, Wander Suero and Austen Williams, the last of whom made his major league debut Sunday and looked promising while working two scoreless frames.

Nationals rookie starter Jefry Rodriguez stuggled Sunday, allowing seven runs and seven walks in 4⅔ innings. (Tommy Gilligan/Usa Today Sports)

And in the rotation is Rodriguez (2-2), whose opportunities have come because of injuries to Stephen Strasburg, Jeremy Hellickson and Tommy Milone this summer. The 6-foot-6 right-hander has made incremental progress, most notably in six scoreless innings the previous Sunday, but his spotty command resurfaced against the Brewers’ lefty-heavy lineup.

He started his outing with six straight balls and finished the first with 25 pitches, two runs on the scoreboard and a loosening grip on the game. The concerns with Rodriguez are that he lacks control and does not have the reliable third pitch that almost every starter needs. On Sunday, those concerns were justified.

“The biggest thing that I learned is that you have to keep battling,” Rodriguez said through team interpreter Octavio Martinez. “I didn’t have the best command out there today, but I never gave up.”

Brewers starter Junior Guerra’s command was not much better, and the Nationals took advantage in a three-run third inning that erased the early deficit. Guerra was lifted after that, just 58 pitches into his start, but Milwaukee soon took the lead back on Keon Broxton’s three-run homer off Rodriguez in the fifth.

In that seven-run inning, the Nationals warmed up lefty reliever Collins as Rodriguez faced the heart of the Brewers’ lineup. But Collins sat down after Rodriguez retired Mike Moustakas, a left-handed hitter, on one pitch. Rodriguez’s pitch count climbed as he gave up another single. Williams, a right-handed reliever, then readied in the bullpen as Broxton crushed Rodriguez’s 2-0 fastball well beyond the center field fence.

Rodriguez stayed in for two more hitters, giving up another single and walking relief pitcher Brandon Woodruff (3-0) on four pitches. His command issues — 100 pitches in fewer than five innings, 50 strikes, 50 balls — were stretched across the scoreboard as he retreated to the Nationals’ dugout. Then Collins served up the first grand slam of Yelich’s career, rounding out Rodriguez’s final line at seven earned runs on seven hits and seven walks in 4⅔ innings.

Nationals Manager Dave Martinez said he wanted Rodriguez to get through the bottom of the order so Collins could start fresh in the sixth. He added that relievers Cordero, Suero and lefty Matt Grace were not available to pitch, slimming his options in the fifth. Collins felt ready to go despite the choppy warmup session. Either way, the results did the Nationals in.

“I don’t think there’s anything normal in the bullpen. Those are situations you just have to adjust to,” Collins said. “Being a bullpen guy, sometimes you’re going to get up and sit down, get up and sit down. It’s just a matter of not flipping the switch off when you have to sit down. That’s certainly not an excuse for what happened today. Just a matter of executing pitches. Shouldn’t happen.”

The Nationals have not wilted easily in recent weeks, even as six key pieces were traded away in the past month, even as August rolled toward September and the results stayed the same. They have turned some nights into glimpses of a competitive future. They have staged late-inning comebacks. They have made many losses feel like fights, even if the standings count them all the same.

Yet there was no such push Sunday.

The Nationals’ offense, after jumping on Guerra, dried up against the Brewers’ bullpen. Washington’s bullpen only ushered the game to a conclusion. And the weekend, once offering the Nationals a cracked window to climb through, ended with another missed opportunity and the feeling that there might not be any of those left.