Rockies vs. Diamondbacks Prediction, Odds, Probable Pitchers and Prop Bets for Friday, Aug. 8

The D-Backs are favored at home against the Rockies.

Arizona Diamondbacks second baseman Ketel Marte is a solid prop target on Aug. 8. / Dennis Lee-Imagn Images

After selling off pieces at the trade deadline, the Arizona Diamondbacks are a long shot to make the playoffs in a crowded National League, but they find themselves as massive favorites at the best betting sites on Friday night. 

Arizona is taking on the 30-win Colorado Rockies, who have the worst record and run differential in Major League Baseball this season.

The Rockies have lefty Austin Gomber (6.18 ERA) on the mound in this matchup against Zac Gallen, who is having a rough 2025 for Arizona.

A former All-Star, Gallen has a 5.48 ERA, and he’s already lost 12 games in the 2025 season. Overall, the D-Backs are just 10-13 when he’s on the mound.

Can he turn things around in this NL West battle?

Here’s a look at the odds, players to watch in the prop market and my prediction for Friday’s matchup. 

Rockies vs. Diamondbacks Odds, Run Line and Total

Odds via DraftKings Sportsbook

Run Line

• Rockies +1.5 (+101)
• Diamondbacks -1.5 (-123)

Moneyline

• Rockies: +197
• Diamondbacks: -246

Total

• 9 (Over -111/Under -109)

Rockies vs. Diamondbacks Probable Pitchers

• Colorado: Austin Gomber (0-5, 6.18 ERA)
• Arizona: Zac Gallen (8-12, 5.48 ERA)

Rockies vs. Diamondbacks How to Watch

• Date: Friday, Aug. 8
• Time: 9:40 p.m. EST
• Venue: Chase Field
• How to Watch (TV): ARID, COLR
• Rockies record: 30-84
• Diamondbacks record: 54-61 

Rockies vs. Diamondbacks Best MLB Prop Bets

Diamondbacks Best MLB Prop Bet

• Ketel Marte to Hit a Home Run (+200)

Earlier today, I shared in SI Betting’s MLB best home run picks – Daily Dinger – why Marte has a great matchup on Friday:

Arizona Diamondbacks switch-hitter Ketel Marte is a frequent flier in my Daily Dinger picks, and he has a great matchup against the Colorado Rockies on Friday night.

Marte is facing Rockies lefty Austin Gomber, who enters this matchup with a 6.18 ERA this season. He’s allowed 10 homers in nine appearances, and Marte has crushed Gomber in his career.

Through 26 at bats against Gomber, Marte has 10 hits, three doubles and three home runs, good for a .385 batting average and a 1.275 OPS.

Now, Marte is hitting just .241 against lefties this season, but he’s still homered five times in 112 at bats. I think he’s worth a shot against a Colorado pitching staff that has the worst team ERA in Major League Baseball. 

Rockies vs. Diamondbacks Prediction and Pick

Even though the Rockies are the worst team in baseball and aren’t exactly an offensive juggernaut, I think we could be in line for a high-scoring game on Friday night.

Colorado has the worst team ERA in MLB, and Gomber has been awful this season posting an 0-5 win/loss record while allowing at least four runs in five of his nine starts. He’s given up 59 hits in 43.2 innings of work, and the Rockies have combined for 10 or more runs in four of his outings.

As for Gallen, he has not been able to turn things around all season long, allowing four or more runs in 14 of his 23 outings. 

Both of these teams have terrible bullpens, as Arizona is 27th bullpen ERA (4.93) and Colorado is 29th (5.53).

I’ll expect both offenses to tee off against these pitching staffs in this series opener. 

Pick: OVER 9 (-111 at DraftKings)

---

Odds refresh periodically and are subject to change.

If you or someone you know has a gambling problem and wants help, call 1-800-GAMBLER.

Claim the latest DraftKings promo code offer today. Sign up and place a $5 bet to earn a guaranteed $150 in bonus bets. Regardless of the outcome of your wager, DraftKings will add six $25 bonus bet tokens to your new account instantly.