(Best E Casino) - A franchise-record road losing streak has the Arizona Diamondbacks on the verge of missing the postseason. The club will try again to solve its road problems when it battles the Colorado Rockies in the second contest of a three-game series tonight at Coors Field.

Arizona trails the Los Angeles Dodgers by 3 1/2 games for first place in the National League West with nine left to play. The Diamondbacks entered this test having swept a four-game home series with the Giants to keep pace, but were edged by Colorado, 3-2, on Friday.

It was Arizona's 11th straight loss on the road, surpassing the franchise- record of 10 consecutive road defeats set from July 10-August 1, 2003. The Diamondbacks are just 31-44 as the visiting club this year.

Chris Iannetta and Clint Barmes each recorded solo homers behind six effective innings from Jorge De La Rosa as the Rockies posted the one-run victory.

De La Rosa allowed just one run on three hits and three walks with six strikeouts for Colorado, which has won four of five after losing seven straight. Garrett Atkins added three hits and an RBI in the win.

Highly-touted Diamondbacks prospect Max Scherzer remained winless after allowing three runs on seven hits with eight strikeouts in a six-inning start.

Mark Reynolds homered for Arizona and teammate Adam Dunn went deep for the 38th time this season. He is second in the majors in long balls, behind only Ryan Howard (46) of Philadelphia.

Doug Davis, one day shy of his 33rd birthday, starts for Arizona tonight and is 6-8 with a 4.30 earned run average on the season. However, the lefty is pitching to a 3.27 ERA over his last seven starts.

Davis hasn't factored into the decision of any of his last three starts. That includes Monday versus the Giants, when he gave up just an unearned run over seven innings of his team's eventual 3-1 victory.

Davis is 2-3 with a 3.34 ERA in six career starts versus the Rockies.

Colorado counters with Aaron Cook, who is still one win shy of matching the club record for most victories in a season.

Cook is 16-9 with a 4.00 ERA and is trying to become the fourth pitcher in club history to win 17 games in a season. He would match the mark held by Kevin Ritz (1996), Pedro Astacio (1999) and Jeff Francis (2007).

Cook, who hadn't won more than nine games prior to this season, got a no- decision on Sunday versus the Dodgers even though he hurled eight shutout frames. The right-hander also didn't walk a batter while working around eight hits.

The 29-year-old is 5-4 with a 5.29 ERA lifetime against Arizona, but has a 6.55 ERA in two tests versus the club this season.

Arizona has won 10 of the 13 encounters with Colorado this season and is 5-2 at Coors Field. The D'Backs have won five of the last seven meetings in this series.