The Post Sports Live crew debates whether the Nationals should make a move to add a missing piece or stand pat before the July 31 trade deadline. (Post Sports Live/The Washington Post)

The Washington Nationals’ hot streak headed toward an unceremonious, ugly finish Wednesday afternoon at Coors Field. Trash whipped around the warning track, fielders shielded their eyes from wind-blown dirt and rain dripped from a gun-metal gray sky. As conditions momentarily worsened late, so, too, did their play.

As soon as the sun broke through, though, the Nationals mounted a final charge that nearly toppled the Colorado Rockies. In the ninth inning of their 6-4 loss, the Nationals scored two runs with four consecutive two-out singles off closer LaTroy Hawkins, then loaded the bases when shortstop Josh Rutledge booted Adam LaRoche’s groundball. The Nationals finally succumbed when Ian Desmond struck out after a seven-pitch at-bat, leaving the tying run in scoring position.

The improbable end only forced the Nationals to look back at so many moments with regret. Stephen Strasburg yielded three runs in the first inning before he settled. Rockies left-hander Jorge De La Rosa struck out 11 hitters over 71 / 3 innings, and still the Nationals created a chance to beat him in the seventh before an ill-conceived, misplaced bunt foiled a rally. The Rockies added two insurance runs in the seventh after Aaron Barrett walked the leadoff batter and catcher Jose Lobaton misfired to first following a dropped third strike.

The Nationals had won six of seven, and hours after they placed Ryan Zimmerman on the disabled list, they threatened to make it seven of eight. Hawkins recorded two quick outs. Pinch-hitter Zach Walters, the call-up who replaced Zimmerman and arrived about an hour before first pitch, flared a single to center.

Denard Span followed with another single, his fourth hit of the game. And then Jayson Werth drilled an RBI single to right. And Anthony Rendon followed with another RBI single. Suddenly, LaRoche walked to the plate as the go-ahead run.

“We gave ourselves a chance again,” Manager Matt Williams said. “It’s the nature of this ballpark. It’s some pretty good at-bats put together against their closer in the last inning.”

LaRoche grounded to shortstop, but Rutledge bobbled the ball. With two outs and the bases loaded, Desmond, the Nationals’ best hitter with the bases loaded, dug in. He took a close 1-2 pitch for a ball and spoiled two more pitches. Finally, Hawkins blew a fastball past him to end the game.

“I was in the at-bat,” Desmond said. “I was happy with where I was at. You got to tip your cap sometimes.”

Strasburg showed resilience Wednesday, but again he came far from dominance. The Rockies slapped nine hits and scored four runs off him in 51 / 3 innings, some bloops but also some missiles. His record dropped to 7-8. In 18 innings over his last three starts, Strasburg has allowed 23 hits, six walks and 10 earned runs. His ERA has grown from 3.47 to 3.67, just shy of the National League average of 3.69.

Still, Strasburg gave the Nationals a chance. The Rockies whacked four hits and scored three runs in the first as he struggled to find feel for his curveball. Pitching at Coors Field for the second time, Strasburg told himself to keep his pitches low in the zone and not concern himself with inducing swing-and-misses.

“I easily could have shut it down,” Strasburg said. “I didn’t want to do that.”

Strasburg punched up four straight scoreless innings, escaping the fifth inning in remarkable, almost stupefying fashion. Rutledge led off with a double to the left field corner. Corey Dickerson followed with a smash to dead center field. Rutledge, tagging up on the play, only advanced to third after the ball caromed off the fence.

After Nolan Arenado ripped a groundout to third, Williams ordered an intentional walk of Ben Paulsen, loading the bases to set up a possible double play.

Up came Drew Stubbs, a speedster batting .302 this year. Strasburg missed badly with a curveball that slipped out of his hands, running the count full. Stubbs had to know Strasburg would likely throw a fastball. Pitching out of the windup, Strasburg threw one with everything he had. It hummed at 98 mph, the hardest pitch he has thrown all season.

“Must be wrong,” Strasburg said afterward. “I was just trying to throw a strike, trying to challenge him.”

One locker over, Craig Stammen heard Strasburg and patted him on the shoulder. “We know it’s still in there,” Stammen said, laughing.

Stubbs hit it off the handle, right at Desmond. He flipped the ball to Danny Espinosa, who rocketed a throw to first to complete the double play. Stubbs slammed his helmet with both hands. Strasburg pumped his fist and walked off the mound.

Strasburg couldn’t survive the sixth, and Ross Detwiler allowed an inherited runner to score on Charlie Blackmon’s bloop to left. With the Nationals trailing 4-2, Lobaton led off the seventh with a single to right. Pinch-hitter Kevin Frandsen followed with a clinical bunt single down toward third base. With no outs, the top of the Nationals lineup loomed with two runners on.

Span, already 3 for 3 with an RBI single, stepped into the box. In the Nationals’ dugout, Werth walked up and down, gray batting gloves on his hands. Williams planned to pinch-hit him for Scott Hairston, and he wanted to give Werth a chance to tie the game with a single.

Span pushed a sacrifice toward third base, but too close to the middle of the diamond. De La Rosa scampered off the mound and scooped the ball. With Lobaton running, Span needed a near-perfect bunt. De La Rosa fired to third and nailed Lobaton.

“We’re going to pinch-hit Jayson there,” Williams said. “We want to get guys to second and third. De La Rosa got off the mound and made a good play. I’m sure if you asked Denard, he’d want a better bunt than that.”

The inning’s momentum had halted. As Werth walked to the plate, wind gusted strong enough to threaten ripping flags off poles, and fans sought cover from rain. Werth struck out, and the threat had been neutralized.

The Rockies added two runs off Barrett, one earned and one coming after Lobaton couldn’t corral a strike-three slider and fired low to LaRoche at first base. The ball skidded away, and a run scored to make it 6-2.

“When he got it, he’s right in the line with the runner,” Williams said. “He tried to feather it in there. It just didn’t work.”