DENVER -- So much of baseball is about timing.

Unfortunately for the D-backs, timing wasn’t on their side on Monday night, when they dropped their series opener against the Rockies at Coors Field, 3-2.

Timing is what cost Arizona in the bottom of the ninth, when with the score tied, 2-2, Geraldo Perdomo didn’t correctly calculate how much time he really had to complete a 4-6-3 double play -- the result was the game-winning run crossing the plate for Colorado.

Timing also cost the D-backs at the plate. The result was Arizona batters hitting into four double plays and zeros on the scoreboard for every inning after the first.

In discussing the game’s final play, Perdomo said that his throw to first, which was errant and got past a diving Christian Walker, was unnecessarily rushed.

“It was a slow ground ball,” Perdomo said, indicating he was anticipating that completion of the back end of a double play would be difficult. “It’s all my fault. I was just rushing a little bit.”

A tenth of a second can make all the difference. With Brendan Rodgers, who hit the slow ground ball to Ketel Marte at second, running, there was more time than Perdomo felt.

Had it been the man who was rounding third on the play -- Brenton Doyle -- heading to first, a hurried throw would have been justified. The fleet-footed Doyle led off the inning with a single, stole second and came all the way around to score on Perdomo’s error.

“I really had more time to make a nice and easy [throw],” Perdomo said. “[I’m] sorry for the guys, they were fighting today. Merrill [Kelly], six innings … but it was all on me right there.”

Kelly, who had to leave his prior start after four innings due to cramping in his right hamstring, went six solid frames in the hitter-friendly Coors Field despite not feeling great. He gave up a run on two hits, walked two and struck out five.

Manager Torey Lovullo pulled Kelly after 83 pitches as a precaution given the altitude and the fact that he experienced cramping in his prior outing.

“Honestly, today I was pretty tired,” Kelly said. “I don’t know if it was just one of those games people talk about in Colorado where the body just has a tough time getting going. And from the first inning, that’s really how I felt.”

The fact that Kelly got the results he did despite how he felt physically is perhaps the silver lining that the D-backs can take from Monday’s loss.

After missing nearly four months due to a right shoulder strain, the right-hander returned to the mound on Aug. 11. But over his first four starts upon returning, he struggled to a 6.75 ERA.

Over Kelly’s last three starts, his ERA is 3.18.

“I still feel like I’m going in the right direction,” he said. “I think today is almost a testament to that. I think if I were in the same spot that I was, [but it was] maybe three or four starts ago, I think the result would have been a lot worse than I did today.”

Kelly kept Rockies hitters at bay. But outside of a two-run first inning, Arizona’s bats were mostly silent, too.

Corbin Carroll opened the game with his MLB-leading 14th triple of the season. That was promptly followed by Ketel Marte’s 32nd homer of the year, a 460-foot shot over the center-field wall.

Following an 11-run performance in Sunday’s wild win over the Brewers, the D-backs -- who have the highest-scoring offense in baseball -- were shut out after the first inning Monday.

A microcosm of Arizona’s impatience at the plate came in the fifth, when D-backs hitters saw three pitches.

“Offensively, these guys are always locked in,” Lovullo said. “So this was an outlier today, offensively. … I think we beat a couple balls into the ground, we hit a couple balls hard that didn’t go our way. I want more patient approaches -- I think that’s what we’re so good at.”

With both the Padres and Mets winning on Monday, the D-backs lost ground in the Wild Card standings -- Arizona is 2 1/2 games behind San Diego for the top NL Wild Card position and one game ahead of New York. The Braves are one game behind the Mets.

As they say, timing is everything. And time in the regular season is running out. For the D-backs to get a chance to make another deep postseason run, they’ll need to recalibrate at the plate.