DENVER -- D-backs ace Zack Greinke's first start in May was at Coors Field. So was his last one. Both times, the right-hander turned in a strong outing but the bullpen couldn't hold a lead in a loss to the Rockies.

In both games, Archie Bradley was on the mound when the Rockies tied it.

Monday’s 4-3, 11-inning loss in a Memorial Day matinee came after the D-backs' offense scored 34 runs in a three-game sweep of the Giants in San Francisco over the weekend.

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There were moments Monday when D-backs hitters didn’t come through, the most glaring coming in the 10th, when Jarrod Dyson was stranded at third after leading off with a triple.

But this game got away in the seventh, when Bradley gave up a two-out, game-tying, two-run single to Nolan Arenado.

The D-backs’ bullpen owned a Major League-best 2.31 ERA in high-leverage situations at the end of April. But this month has been a relief corps rollercoaster that has led manager Torey Lovullo to seek what he calls “the little victories” among his relievers.

“I liked the matchup,” Lovullo said of Bradley vs. Arenado. “I’ve thought that through 1,000 times since the game was over. But I’m going to stand by it. … I wanted to see if that big out would get him on a roll. I know he’s been grinding, he’s had some really good games as of late, he’s made some adjustments and it was his time.

“We look for little push moments, momentum swingers for guys. … And I thought that was the right situation.”

Bradley, like most of Arizona's bullpen, has had his ups and downs this month. He entered May with a 1.50 ERA, and since, that mark is 6.97, though he had posted three consecutive scoreless outings heading into Monday. He wasn’t charged with the two runs that scored on Arenado’s single -- those went to Yoshihisa Hirano, who allowed a hit and a walk in two-thirds of an inning.

Lovullo took the chance that a red-hot Arenado, who was 8-for-20 with a double, two triples and two homers against Bradley, wouldn't deliver again. Another option was right-hander Yoan Lopez, a hard-throwing rookie against whom Arenado was 0-for-2 with a strikeout.

Lovullo went for the momentum play that he hoped would pay dividends down the road.

“I’m constantly searching for those types of moments, putting them into big situations and having them walk off the mound and know they had a tremendous accomplishment,” Lovullo said. “This is a game of confidence.”

It’s a tightrope to walk, balancing an individual player’s potential confidence boost with the strategy the situation dictates. But Lovullo doesn’t regret how he walked it. He said he didn’t want to use Lopez to get one out because he also didn’t know if he’d want to use him in the eighth in that situation.

Lovullo planned to bring in Lopez for a clean-slate eighth, then go to closer Greg Holland in the ninth.

“I’m not going to put one guy’s potential momentum push ahead of the team,” Lovullo said. “I actually believed in that matchup. We do a lot of work here, and that matchup told me it was very, very good.”

Arizona’s bullpen has thrived and struggled in the first two months of the season. But when Matt Andriese gave up an Ian Desmond double, followed by a Raimel Tapia walk-off RBI single to end the game in the 11th, the pendulum was firmly on the “struggled” end of the spectrum.

So, Lovullo will continue to look for those “push moments” going forward.

“That’s the beauty of this game,” Lovullo said. “I’ve got to sleep on that one for the rest of the year. That’s what you’ve got to love about it, and sometimes you hate about it.”