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04/20/10 2:45 AM ET

Lopez holds his end of bargain; 'pen doesn't

Arizona drops fifth straight game, falling to St. Louis at home

PHOENIX -- With the Cardinals at Chase Field for two more games this week, starting on Tuesday night -- and the Phillies to follow for a three-game weekend set -- the D-backs are evidently on the cusp.

They have lost five in a row, including Monday night's 4-2 decision to the defending National League Central champions, and with the two-time NL-pennant winners coming in, the D-backs must pick up the pace. At 5-8, they are again nestled in last place in the NL West.

"We've got to find ways to make plays and win games," D-backs manager A.J. Hinch said. "We're falling short. And we're getting reminded of that daily during this slide we've been in."

The D-backs received the start they needed out of veteran right-hander Rodrigo Lopez on Monday night, but they had to hand the game over to the bullpen in the eighth.

For the fourth time in the past five games (all losses), the bullpen trap door opened and the D-backs fell through. In those five games, the starters have allowed just six runs in 30 1/3 innings for a 1.78 ERA. The bullpen has allowed 18 runs during that same span.

Blaine Boyer was the culprit who allowed the winning run, with an assist from first baseman Adam LaRoche. And Chad Qualls let up the insurance tally in the ninth. Colby Rasmus drilled Boyer's second pitch for a double and went to third on a sacrifice bunt. LaRoche, back after missing three games with a sore right quad, booted Yadier Molina's grounder for a key error, allowing the go-ahead run to score.

"We needed [Boyer] to get a ground ball there, and he did it on the first pitch," LaRoche said. "I screwed up. I've got to come up with that play. That's what we wanted. If I come up with that, we could've saved that run. We got the ground ball, and I didn't come up with it."

LaRoche isn't playing at nearly 100 percent. Before the game, left fielder Conor Jackson was placed on the 15-day disabled list because of a strained right hamstring. He joined catcher Miguel Montero on the list. Montero is recovering from surgery last week to repair a meniscus tear in his right knee.

That the D-backs are playing short right now is an understatement. They're using 12 position players, and Hinch burned them all through regulation trying to find the right combination to plate the winning run. For instance, on two occasions his club couldn't get down a bunt, forcing a runner at second base rather than moving him over.

With runners on the corners and one out in the seventh, Stephen Drew grounded into a rally-killing double play.

"I was leaving the ball up a lot the [previous] inning, so I was just trying to get a ground ball," said Cardinals starter and winner Brad Penny, who left after seven having allowed two runs on eight hits.

An inning later, the D-backs couldn't generate any run production with one out and runners on first and second against a pair of St. Louis relievers.

"Small things that are grouped together are leading to bad outcomes," Hinch said. "Regardless of whether it's the offense, the bullpen, the starting pitching going deep into games, we've got plenty of good players to pick up the slack. I'm not going to sit here and dwell on the injuries we've had. We have guys here in the big leagues, who need to make plays and come through when they're given the opportunity."

Lopez, who had Tommy John surgery two years ago and made the club as its fourth starter during Spring Training, turned in a gutty performance. He piled up the pitch count early, but held the Cards at bay until he was replaced for a pinch-hitter in the bottom of the seventh.

The Cards had a pair of runners on base in each of the first four innings to no avail before Matt Holliday hit a two-run homer in the fifth to tie the score at 2.

Lopez wasn't around for the decision, but he threw 109 pitches, allowing two runs on seven hits (including Holliday's fourth homer), walked four and struck out three.

He had thrown 61 pitches through three innings, 72 through four, and it looked like Hinch might have to go to his beleaguered bullpen early. Lopez then settled down and turned the game over to the bullpen later, again with the same recent results.

"It's frustrating," Lopez said. "It's frustrating to lose late in the game. No question, we've been struggling. We just have to continue to do our job. The bullpen is going to be fine and we're going to get back on track."

It's only late April, but the days on the baseball schedule are already ominously counting.

Barry M. Bloom is a national reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.