Giants vs. Diamondbacks Prediction, Odds, Probable Pitchers and Prop Bets for Monday, June 30

Betting odds, pick and prediction for the San Francisco Giants-Arizona Diamondbacks matchup on Monday.

The San Francisco Giants are favored with starting pitcher Logan Webb on the mound. / Sergio Estrada-Imagn Images

Two NL West teams are aiming to snap losing streaks on Monday, as the San Francisco Giants take on the Arizona Diamondbacks.

Arizona has lost four games in a row, falling to one game under .500 in the 2025 season and 11 games back of the Los Angeles Dodgers in the division. The Giants, on the other hand, dropped their final two games over the weekend and are 7.5 games behind the Dodgers in the standings.

Luckily for San Francisco, All-Star Logan Webb is on the mound on Monday with a chance to stop the streak against Arizona’s Ryne Nelson.

Oddsmakers have the Giants set as road favorites in this matchup, but can they keep this vaunted Arizona offense in check?

Here’s a breakdown of the odds, players to watch in the prop market and my prediction for Monday’s divisional battle. 

Giants vs. Diamondbacks Odds, Run Line and Total

Odds via DraftKings Sportsbook.

Run Line 

• Giants -1.5 (+117)
• Diamondbacks +1.5 (-143)

Moneyline

• Giants: -145
• Diamondbacks: +119

Total

• 8 (Over -112/Under -108)

Giants vs. Diamondbacks Probable Pitchers

• San Francisco: Logan Webb (7-5, 2.52 ERA)
• Arizona: Ryne Nelson (4-2, 3.71 ERA)

Giants vs. Diamondbacks How to Watch

• Date: Monday, June 30
• Time: 9:40 p.m. EST
• Venue: Chase Field
• How to Watch (TV): Fox Sports 1, ARID, NBCS-BA
• Giants record: 45-39
• Diamondbacks record: 41-42 

Giants vs. Diamondbacks Best MLB Prop Bets

Giants Best MLB Prop Bet

• Rafael Devers to Hit a Home Run (+270)

Earlier today, I shared in SI Betting’s best home run picks – Daily Dinger – why Devers is worth a bet against this weak Arizona pitching staff: 

Devers and the Giants are taking on Ryne Nelson and the Diamondbacks, and there are several reasons to expect an offensive explosion from the Giants in this game.

First off, Nelson has recently moved from the bullpen to a starting role, and while he has a solid 3.71 ERA for the season, the young righty has given up a home run in three of his four starts in June. 

Not only that, but the bullpen behind Nelson is extremely weak. The D-Backs rank 28th in MLB in bullpen ERA (5.31), and they’ve allowed 43 home runs as a team so far in the 2025 season. 

That should give Devers plenty of chances to go deep, and he has hit two homers over the last two weeks (12 games) for the Giants. While Devers is hitting just .217 over that stretch, he has thrived against right-handed pitching, hitting 12 of his 17 homers this season against them.

Giants vs. Diamondbacks Prediction and Pick

This game just so happens to feature another one of my favorite bets, as it’s hard to fade the Giants when Webb is on the mound.

I broke down why I think San Francisco wins this series opener in today’s MLB Best Bets column at SI Betting: 

Logan Webb is on the mound for the Giants, which means we’re backing San Francisco to pick up a win. 

So far this season, Webb has a 2.52 ERA and a 2.25 Fielding Independent Pitching, leading the Giants to a 9-8 record across 17 starts. He’s allowed more than three earned runs in just one of his 17 outings in 2025.

On top of that, Webb has thrown at least six innings in every start in June, posting a 1.85 ERA. His advanced numbers back up his 2025 season, as he ranks in the 82nd percentile in expected ERA (3.02).

Meanwhile, the D-Backs are relying on Ryne Nelson, who has moved back into the rotation after spending much of the season coming out of the bullpen. Nelson has a solid 3.71 ERA, but the bullpen behind him ranks 28th in Major League Baseball in ERA at 5.31. 

The D-Backs have been a potent offense this season, but the Giants have the best bullpen ERA (2.91) in baseball. With Webb on the mound, San Francisco should be able to steal a road win on Monday. 

Pick: Giants Moneyline (-145 at DraftKings)

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Odds refresh periodically and are subject to change.

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