DENVER -- The race is on -- and certainly not the one the Padres were anticipating at this time of year.

In a wild finish at Coors Field on Monday night, the Rockies walked off with a 6-5 victory on C.J. Cron’s opposite-field blast, mere moments after Trent Grisham had tied the game with a three-run shot in the top of the ninth.

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It was a particularly crushing blow, as the Reds, meanwhile, were delivering a statement victory over the Cubs. Don’t look now, but things are getting awfully tight in the National League Wild Card race.

After entering the season with their sights set squarely on a division title, the Padres suddenly find themselves clinging to the second Wild Card spot. With Monday’s loss, San Diego’s lead dwindled to 1 1/2 games -- the smallest it’s been since June 20.

“We haven’t been pulling off a lot of these games, but everybody in this clubhouse believes in each other,” Grisham said. “All we can do is go out there and keep giving it all we’ve got.”

Left-hander Ryan Weathers was roughed up for a fourth consecutive outing, allowing five runs over four innings. Three weeks ago, the rookie Weathers had never allowed five runs in a big league outing. He’s now allowed at least that many in four straight.

“It feels like right now, any mistake I make, they’re just not missing,” Weathers said.

Perhaps most telling was the Padres’ decision-making involving Weathers on Monday. With the top of the Rockies’ order due up in the fifth inning, manager Jayce Tingler gave Weathers a quick hook, in favor of his bullpen. Never mind that Weathers had only thrown 62 pitches, and never mind that there’s serious uncertainty regarding how the Padres cover the next two games at Coors Field.

“We’re just taking the approach of doing everything in our power to win the game,” Tingler said. “Worry about tomorrow tomorrow. That’s been the approach.”

Considering the standings, that sense of urgency is probably warranted. Tingler's quick hook paid off in the form of four scoreless innings from Austin Adams, Nabil Crismatt and Miguel Diaz.

The Padres' offense, meanwhile, did its best to claw back into the game, and finally broke through in the ninth. Down to their final out, Grisham swatted an opposite field blast that sent the visiting dugout into a frenzy.

The excitement was short-lived. Daniel Hudson threw Cron a slider that caught too much plate, and the Rockies slugger made no mistake. The Padres were left reeling, having lost five of their last six games -- against three teams squarely outside of the playoff picture.

“It sucks,” Grisham said. “But it doesn’t change the fact that we’ve got to show up tomorrow and try to win another ballgame. That’s all we can do as players is keep our heads down and keep grinding.”

For the past month, the Padres’ starting pitching depth -- or lack thereof -- has been the topic du jour. It was never quite as glaring as it was on Monday, however. With Yu Darvish (lower back tightness) and Chris Paddack (left oblique strain) on the injured list, San Diego signed Jake Arrieta to a Minor League deal. They’ll ask Arrieta, who posted a 6.88 ERA in 20 outings with the Cubs this season, to fill one void in their starting rotation. He will get the ball Wednesday.

As for Tuesday, the Padres were still uncertain how they’d cover nine innings as of the final out on Monday night. It comes on the heels of Weathers’ early exit, which may have ruled out both Diaz and Crismatt as starting options.

And therein lies the delicate balance the Padres must strike these days. Their rotation depth is thin, and they need their starters to cover innings. But their Wild Card lead is also thin, and they can’t afford to watch their starters struggle.

Rockies leadoff man Connor Joe had homered and singled against Weathers, and when his turn came up in the top of the fifth, Tingler decided he couldn’t let his team fall into a deeper hole.

“At this stadium, if you can keep it within a reasonable mark, you feel like you’re in the game,” Tingler said. “Getting back to the top of the order, I thought Connor Joe had taken some good swings off of him, and so that was the decision there.”

That decision paid off. And then it didn’t, with the Padres left scrambling to find enough pitching for the remainder of the series. Scrambling to find a way to hold off the fast-charging Reds.

“We’ve got enough ability,” Tingler said. “We’ve got enough talent. We’ve got the guys. We can do this. There’s a ton of belief. It’s not just from me, it’s from within. … We’ve got to find a way.”