PHOENIX -- Torey Lovullo can’t explain it, and the D-backs’ manager would prefer not to talk too much about it, lest his players start allowing it to seep into their heads.

But the fact remains that the D-backs have not played as well at Chase Field as they have on the road.

The latest example came Tuesday night when they opened a nine-game homestand with an 8-1 loss to the Rockies.

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That dropped their record at home this year to 14-17, as opposed to a 24-19 mark on the road. They’ve now lost six straight to the Rockies.

“I can’t explain it,” Lovullo said. “I don’t want anybody to think that it’s more of an issue than it actually is. I think we’re just a good baseball team. We’re going to bang the baseball no matter what. Just every once in a while, you hit a bump in the road.”

During their recent 10-game road trip, the D-backs pounded opposing pitchers, scoring a club-record 26 runs while going 7-3.

On Tuesday, though, Antonio Senzatela, who came into the game with a 5.48 ERA, managed to hold them to one run over 6 2/3 innings.

More than whether they were playing at home or on the road, it was the D-backs’ offensive approach that needed to change. Too many times they fell behind with early-count swings or made outs early in the count rather than make Senzatela (6-5) work.

“We’ve just got to grind a little bit when somebody’s feeling it on the mound and find a way to score some runs,” Lovullo said.

This is a crucial homestand for the D-backs. In addition to three games against the Rockies, they also host the Giants and Dodgers for three.

Then they go on the road for four in San Francisco and two in Los Angeles before wrapping up the first half with a three-game homestand against the Rockies.

With so many teams bunched up in the National League Wild Card race, the D-backs need to get a little bit of separation if they want general manager Mike Hazen to add reinforcements before next month’s Trade Deadline.

The Phillies and Cubs lead the Wild Card standings with the Rockies a game back and the D-backs and Cardinals both two behind. The Padres are nipping at their heels, just three back.

“With all the teams we’re talking about, if you tread water, you’re moving backwards,” Hazen said.

While Merrill Kelly gave up a two-run homer to Nolan Arenado in the first inning, he managed to settle in and keep them off the board over the next four innings.

The D-backs’ offense, though, could push across just one run against Senzatela. When the Rockies blitzed them with a four-run sixth, it was too much for Arizona to overcome.

“I feel like it’ll even out,” outfielder Jarrod Dyson said. “I feel like we’ll get rolling at home soon. As of late, we’ve been doing most of our damage on the road. At the same time, our goal is to defend home. It’s good we’re playing good somewhere. On the road, we’ll take that. But at the same time, we’ve got to clean up our homestands and do a better job.”