Colorado @ Arizona preview

Last Meeting ( Aug 8, 2014 ) Colorado 3, Arizona 5

The Arizona Diamondbacks try for their sixth straight victory over Colorado when they host the struggling Rockies on Saturday in the middle contest of a three-game series. Arizona prevailed 5-3 on Friday as Colorado fell to 2-19 in its last 21 road games and a major league-worst 17-40 away from home. The Diamondbacks' Miguel Montero continued his assault on Rockies' pitching with a three-run homer and has four homers and 13 RBIs in 10 games against Colorado this season.

The Rockies, who lead the major leagues in hitting (.279) — including an eye-popping .317 at home — are a different team on the road with a .238 average — third-worst in baseball. Arizona, which has won two of its last seven games, is 4 1/2 games clear of last-place Colorado in the National League West. The Rockies' Jorge De La Rosa had a five-game winning streak snapped in his last turn and opposes Trevor Cahill, who is winless in four starts (0-2) since returning to the rotation.

TV: 8:10 p.m. ET, ROOT (Colorado), FSN Arizona

PITCHING MATCHUP: Rockies LH Jorge De La Rosa (11-7, 4.27 ERA) vs. Diamondbacks RH Trevor Cahill (1-8, 5.12)

De La Rosa yielded four runs and six hits while striking out six in 6 2/3 innings of a 4-0 loss in Detroit on Sunday to snap a seven-start unbeaten streak and fall to 4-5 with a 5.29 ERA on the road. The 33-year-old Mexican has made eight straight starts of at least six innings — one shy of matching his career high — and is 5-1 with a 3.53 ERA during that span. De La Rosa is 8-6 with a 2.65 ERA in 22 games (18 starts) against Arizona, including 0-1 with a 4.77 ERA in two starts this season.

Cahill received a no-decision after allowing one run and seven hits while striking out seven in seven innings — his best start of the season — in Arizona's 3-2 victory over Pittsburgh on Sunday. The 26-year-old Californian is 0-6 with a 6.35 ERA in eight starts this season, but sports a more respectable 4.09 ERA in his last four turns. Cahill is 3-5 with a 4.55 ERA in 12 games (nine starts) against Colorado, including three relief appearances covering three innings (one run, two hits) in 2014.

WALK-OFFS

1. Diamondbacks rookie RF David Peralta on Friday stole home when he timed C Michael McKenry's lazy toss back to LHP Rex Brothers, who fumbled it and could not get off a return throw. Peralta also drove in a run with a triple, doubled and scored twice to raise his average to .314.

2. Rockies 3B Nolan Arenado is hitting .297 with zero home runs and 10 RBIs in 138 road at-bats compared to .274 with 10 homers and 33 RBIs in 168 home at-bats.

3. Arizona on Friday selected the contracts of OF Xavier Paul and LHP Andrew Chafin from Triple-A Reno and optioned INF Nick Ahmed and OF Roger Kieschnick to Reno.

PREDICTION: Rockies 3, Diamondbacks 2