Daniel Murphy acknowledges the applause from Nationals fans in his return after being traded to the Cubs. (Jonathan Newton/The Washington Post)

These games could have been so meaningful, so fraught with tension, so exciting. This National League Division Series rematch, staged a month before October, might have carried so much importance or promise or intrigue or . . . well, anything.

Instead, it serves as a reminder of what the Washington Nationals might have been and how far they have fallen now that two key pieces of their roster play in Chicago Cubs blue.

Even as the Nationals and Cubs dueled through lead changes and close calls for 10 innings, the edge was dull, the desperation gone.

When David Bote — the perpetrator of the grand slam that some speculate ended the Nationals’ playoff hopes — hit an RBI double over Victor Robles’s leaping try in the top of the 10th inning, it served as further evidence of how far the team has declined and how many key pieces are no longer here to help it rise. The Nationals lost, 6-4, and fell three games under .500 for the first time since April 30, when they were 13-16.

So much has changed since these teams’ previous series in mid-August, a white-knuckle affair at Wrigley Field. The Nationals could have won three games in that series and somehow lost two — the second on a walk-off grand slam that prevented them from climbing 4½ games back in their division.

In the weeks since, the team has declared its own surrender and fallen out of shouting distance, a process that included trading Daniel Murphy to those same Cubs who beat them in the playoffs. That series at Wrigley Field sent the Nationals reeling.

The Nationals ran a video tribute to Murphy before the game, a new tradition they also applied to Gio Gonzalez last week — a tradition they probably did not anticipate creating because of late-season sell-offs, more evidence of how little expectations and reality aligned.

Murphy led off for the Cubs. Stephen Strasburg teased him into popping out to Wilmer Difo, his replacement at second, on a 92-mph fastball in a moment that summed up the entire reason Murphy is in a Cubs uniform in the first place. Strasburg, still not pitching like his old hard-throwing self, missed 2½ months in which the rotation crumbled around him.

Murphy missed two months in which Difo — serviceable but not a batting title contender — was required to pick up his production. Those and other similar problems rendered this team unable to contend — or unable to believe it could contend — forcing it to sell pieces in late August that signaled a meaningless September. The Nationals contained Murphy Thursday, limiting him to a 1-for-5 showing — far less damage than Murphy inflicted on the Mets when he faced his other former team over the years.

That Strasburg’s fastball is sitting around 92 represents cause for concern, in part because his history suggests that any aberration signals trouble. No matter his health, the drop in velocity had not undone him entirely. He had allowed two runs over six innings in consecutive starts.

On Thursday, he nearly did the same thing.

He allowed two runs on three hits to the Cubs in the third and an unearned run in the fifth. He got two outs in the fifth before Manager Dave Martinez pulled him after 111 pitches. He allowed two earned runs on six hits, another just-fine outing from a pitcher paid to be dominant — though he seems convinced he is healthy.

“It’s getting better,” Strasburg said. “Velocity isn’t quite there just yet, but the life is there, so I think that’s a positive.”

Strasburg’s resurgence would matter far more if this team were headed to the postseason, if these games were helping them gain ground in the NL East. Instead, they are slipping — slipping despite a remarkable tendency to keep themselves in games late, a habit some would interpret as an endorsement of their character.

“That’s just a testament to the players we have,” shortstop Trea Turner said. “We’re not giving anything away. That last inning is just as important as the first.”

The Nationals came back to take the lead on Mark Reynolds’s homer in the fourth. After the Cubs tied the game with an unearned run in the fifth, Turner answered with an RBI single in the bottom of the inning. The Cubs tied the game against Justin Miller in the eighth, taking advantage of the relative inexperience of this bullpen, which was torn apart by injuries and trades. These teams seem destined to play back-and-forth games like this. These ones don’t feel the same. These last games are not as important as the first.

So when Jimmy Cordero — who had never appeared in a major league game before this season and certainly was not on the bullpen radar in spring training — surrendered two runs on three hits, it wasn’t devastating this time. The Nationals could not go home brokenhearted. This time, it felt like reality putting its stamp on a team that has been slow to accept it and that will have to fight simply to finish the season with a winning record, let alone anything more.