The Diamondbacks did not blow a late lead or make any awful mistakes on Thursday night. They generally pitched well and took decent at-bats. They even pulled off a play so sneaky it seemingly caught everyone in the ballpark off guard.

There was nothing particularly poignant about their 4-3 loss to the Colorado Rockies other than the fact that it was another loss. This time, they were beaten more than they beat themselves.

The days keep falling off the calendar and the Diamondbacks keep drifting farther from respectability. At 37-46, they have fallen back to a season-high nine games under .500.

It has been a strange week for them. They endured a gut-wrenching loss on Sunday at Coors Field, blowing a 5-0 lead with their ace on the mound. They bounced back to beat the San Francisco Giants twice in as many days and were in position for a three-game sweep before another late lead got away from them.

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Then came Thursday night. Rather than showing that their series victory over the Giants was a springboard, they again fell short. They put men on but couldn’t deliver one last, big hit. They twice came within inches of cutting down runners at the plate, but their throws were a split-second late. They went back and forth with the Rockies, then gave up a run in the ninth and for once could not answer.

“They scored, we answered, they scored we answered,” Diamondbacks third baseman Josh Rojas said. “We were in it the whole time, they just scored one more than us there at the end.”

At various points in the past six weeks, the Diamondbacks have looked close to putting things together, looked ready to go on a run that could turn their season around. They even had stretches in which the schedule appeared to be in their favor, with matchups against struggling teams. Every time, they have been unable to do so. They have not won three games in a row since mid-May.

“I don’t want to use our youth as an excuse,” manager Torey Lovullo said. “It’s not in our vocabulary. We’ve got good young players that are going out there and grinding away at it and helping us win games.

“I’ve heard some of our starting pitchers comments about closing the gap up and winning the games we’re supposed to win. I agree with those comments. This one was a little bit more of a grind.”

There were some encouraging developments. Left-hander Dallas Keuchel logged seven strong innings, the best of the three starts he has made since joining the Diamondbacks last month. Carson Kelly homered, singled and drove in all three of the Diamondbacks’ runs, the latest indication he is distancing himself from his miserable start to the year.

Then there was the baserunning play Rojas pulled off in the seventh. He was on first when Daulton Varsho hit an uneventful fly ball to center for the second out of the inning. The ball came back to the infield and was relayed to pitcher Lucas Gilbreath. Everything about it was routine.

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Rojas stepped off first and began walking casually toward second. He glanced at the Rockies’ middle infielders. They were moving away from second base, their backs to the ball.

“I got three or four steps before I realized, ‘It’s there. I’m going to take it,’” Rojas said. “So I took it.”

He did so easily, getting there without a throw, with neither shortstop Jose Iglesias or second baseman Brendan Rodgers anywhere close. Rojas said the deciding factor was how far away from the bag the middle infielders were. He needed to know they wouldn’t be able to beat him there.

“Obviously, once I take off they’re going to alert (Gilbreath) and he’s going to turn to throw to somebody,” Rojas said. “They’re the only two guys I have to worry about. Once they got far enough away, it was like, ‘It’s just me and the pitcher.’ I felt pretty comfortable about it.”

He was stranded at second when Geraldo Perdomo bounced out to end the inning. The Diamondbacks had another chance to score in the eighth, as well, putting two on with two out, but Rockies reliever Carlos Esteves struck out pinch-hitter Alek Thomas.

The Rockies went ahead in the ninth on consecutive hits to open the inning off Diamondbacks closer Mark Melancon. Jose Iglesias shot a single to left. Randal Grichuk followed by inside-outing a fly ball to right-center. Iglesias barely beat Perdomo’s relay throw to the plate.

And so another day passed with another Diamondbacks loss — another winnable game that slipped away from them.

“We make some mistakes along the way that don’t allow us to maybe win that extra inch,” Lovullo said. “It happens in this game. We’ve got to find a way to turn the page and get it going tomorrow.”

Reach Piecoro at (602) 444-8680 or nick.piecoro@arizonarepublic.com. Follow him on Twitter @nickpiecoro.

This article originally appeared on Arizona Republic: Rockies beat Melancon in 9th, take series opener over Diamondbacks