DENVER – For perspective on Jordan Montgomery’s return to the rotation for his first start since Aug. 21, when he was moved to the bullpen, it’s worth noting that he watched Monday’s game from the D-backs' center-field bullpen. Manager Torey Lovullo said he’d never seen a starter watch the game from out there before.

“I have fun in the 'pen,” Montgomery said. “A lot of ‘Let's go D-backs,’ and we score when I do that, so I'm sure they want me back there.”

As much as he enjoyed the relaxed atmosphere among the relievers, he was eager to be back on the hill at the start of the game, though Tuesday’s tilt may not have been as much fun as he’d hoped. There may have been some rust as he made his debut performance at Coors Field, but it would have taken a long line score of goose eggs to best Rockies righty Ryan Feltner as the D-backs fell, 8-2, and clinched a rare series loss to Colorado.

The loss dropped the D-backs into a tie with the Mets for the final two National League Wild Card spots, two games ahead of the Braves and 2 1/2 games back of the top Wild Card spot held by the Padres, who lost in extras Tuesday night.

“I'm grateful that nobody's running away with it, but that's a minimal concern,” Lovullo said. “I want to just go and play our game.”

Montgomery threw 79 pitches, 50 for strikes, but he lasted only 4 2/3 innings, allowing three runs on six hits and two walks while striking out four.

“Control of everything was pretty good,” Montgomery said of his first start in nearly a month. “I tried not to think about all the rumors of the ball flying and stuff not moving.”

He had good success with his curve, calling it his best pitch on the night.

“They didn't seem to be seeing it,” Montgomery said. “They kept swinging at it, so [I told myself] if I was going to get beat, I was going to be beat with that.”

The Rockies took the lead on back-to-back doubles to open the second. Michael Toglia led off with a double on what looked like a routine fly on the right-field grass, an area Montgomery called “the triangle of death.” Neither second baseman Luis Guillorme, first baseman Christian Walker nor right fielder Corbin Carroll could track the ball, losing it in the twilight as it dropped between the three of them. Jacob Stallings plated Toglia with a double to right and came around to score on a two-out double to left from Jordan Beck.

“All three players couldn't find it -- they were totally blind,” Lovullo said. “The night sky here can be a little bit challenging.”

In the third, Ezequiel Tovar knocked a solo homer to right, his second round-tripper in as many games to extend the lead to 3-0, which was all the runs the Rockies would need.

The D-backs got on the board in the fourth when Pavin Smith hit his second leadoff double of the game. Jake McCarthy put down a sacrifice bunt and Eugenio Suárez plated Smith with a groundout to short, the only run Feltner gave up on the night.

“We might not be feeling comfortable at the plate,” Suárez said. “They've been pitching well, and they got us. Sometimes you don't have the result that you want. We got one more game here tomorrow, and we got to come with a better energy and try to win the game and go to Milwaukee, see what happens there.”

The Rockies padded their lead in the bottom of the sixth when catcher Jose Herrera’s throw to third in an attempt to thwart a double-steal evaded Suárez, ultimately leading to three more runs.

“That [ball] made a late move, like a sinker,” Suárez said of the throw that got away from him. “I should have caught it.”

The D-backs bullpen ended up yielding five runs, with Scott McGough giving up two runs in his first inning since Aug. 10 and Blake Walston giving up three runs (two earned) in the eighth.

Arizona managed just two runs on six hits, matching its run total from the previous night in the hitter-friendly park.

“Probably swinging through some hittable pitches, things in the zone that we normally handle,” Lovullo said of his team’s subpar offense. “I can't explain coming into this stadium and scoring a couple runs on back-to-back days. We got to figure this out.”