Diamondbacks vs. Rockies Prediction, Odds, Probable Pitchers and Prop Bets for Friday, June 20

Betting odds, pick and prediction for the Arizona Diamondbacks-Colorado Rockies matchup on June 20.

Arizona Diamondbacks second baseman Ketel Marte is a great prop target on Friday. / Dan Hamilton-Imagn Images

The Colorado Rockies failed to complete a sweep of the Washington Nationals on Thursday, but they still took three of four games to give them some solid momentum heading into their weekend series with the Arizona Diamondbacks.

Arizona is .500 in the 2025 season, but it is in fourth place in the NL West – eight games back of the first-place Los Angeles Dodgers. The D-Backs have scored the fourth-most runs in baseball this season, but their pitching staff has been awful, ranking 25th in the league in ERA.

On Friday, Zac Gallen (5.19 ERA) is aiming to turn his 2025 season around for Arizona against Colorado’s Austin Gomber, who tossed five scoreless innings in his first start of the campaign on June 15.

Let’s break down the odds, players to bet in the prop market and my prediction for Friday’s series opener. 

Diamondbacks vs. Rockies Odds, Run Line and Total

Odds via DraftKings Sportsbook.

Run Line

• D-Backs -1.5 (-127)
• Rockies +1.5 (+104)

Moneyline

• D-Backs: -187
• Rockies: +152

Total

• 12 (Over -109/Under -111)

Diamondbacks vs. Rockies Probable Pitchers

• Arizona: Zac Gallen (4-8, 5.19 ERA)
• Colorado: Austin Gomber (0-0, 0.00 ERA)

Diamondbacks vs. Rockies How to Watch

• Date: Friday, June 20
• Time: 8:40 p.m. EST
• Venue: Coors Field
• How to Watch (TV): COLR, ARID
• D-Backs record: 37-37
• Rockies record: 17-58

Diamondbacks vs. Rockies Best MLB Prop Bets

Diamondbacks Best MLB Prop Bet

• Ketel Marte to Hit a Home Run (+230)

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

Arizona Diamondbacks star Ketel Marte has a favorable matchup against the 17-win Colorado Rockies and left-hander Austin Gomber tonight.

In his career against Gomber, Marte is hitting 8-for-23 (.348) with a pair of home runs and a 1.096 OPS. Gomber has only made one start this season, pitching five scoreless innings, but he’s coming off a 2024 campaign where he allowed the most home runs (30) in MLB.

Marte has 12 homers so far in 2025, and he is in a great spot against a Rockies pitching staff that is 29th in MLB in ERA.

Diamondbacks vs. Rockies Prediction and Pick

The 2025 season has been a rough one for Gallen, as he’s allowed four or more runs in nine of his 15 starts.

As a whole, the Arizona pitching staff has struggled, ranking 28th in bullpen ERA and 25th in overall ERA. Colorado isn’t any better, ranking 29th in MLB in team ERA this season.

While Gomber did pitch well in five innings in his first start of the season, he’s coming off a 2024 campaign where he had a 4.75 ERA, 1.30 WHIP and allowed the most home runs in the National League.

This Arizona offense – fourth in runs scored and third in OPS – should tee off against Gomber and the rest of this Colorado staff. 

The OVER is 36-33-5 in Arizona’s games this season, one of the 10-best marks in MLB. 

Pick: OVER 12 (-109 at DraftKings)

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Odds refresh periodically and are subject to change.

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