Red Sox vs. Giants Prediction, Odds, Probable Pitchers and Prop Bets for Saturday, June 21

The Giants are favored at home in Game 2 of this three-game set.

Boston Red Sox starting pitcher Brayan Bello is a pitcher to fade on Saturday. / Eric Canha-Imagn Images

The Boston Red Sox picked up a win in their series opener against the San Francisco Giants and Rafael Devers, but they find themselves as slight underdogs in Game 2 of this series even with Brayan Bello on the mound.

Bello (3.49 ERA) has pitched pretty well for Boston as of late, but some of his advanced numbers (which I’ll break down later) suggest that he’s due for some regression in his coming starts.

The Giants will counter with 26-year-old Landen Roupp, who has a 3.99 ERA so far in the 2025 campaign.

San Francisco is looking to keep pace with the Los Angeles Dodgers in the NL West, so it can’t afford too many losses to a Boston team that is on the outside looking in of the playoff picture in the AL. 

Let’s take a look at the odds, players to bet on in the prop market and my prediction for Saturday’s action. 

Red Sox vs. Giants Odds, Run Line and Total

Odds via DraftKings Sportsbook.

Run Line

• Red Sox +1.5 (-204)
• Giants -1.5 (+165)

Moneyline

• Red Sox: +100
• Giants: -122

Total

• 8 (Over -103/Under -119)

Red Sox vs. Giants Probable Pitchers

• Boston: Brayan Bello (3-1, 3.49 ERA)
• San Francisco: Landen Roupp (4-5, 3.99 ERA)

Red Sox vs. Giants How to Watch

• Date: Saturday, June 21
• Time: 4:05 p.m. EST
• Venue: Oracle Park
• How to Watch (TV): NBCS-BA, NESN
• Red Sox record: 40-37
• Giants record: 42-34

Red Sox vs. Giants Best MLB Prop Bets

Red Sox Best MLB Prop Bet

• Brayan Bello 3+ Walks Allowed (+145)

Through 11 starts, Bello has walked three or more batters five times, posting a walk percentage of 10.8 –  which is in just the 18th percentile amongst all MLB pitchers. 

The Giants have drawn 277 walks in the 2025 season – the third-most in MLB – so I wouldn’t be surprised to see them work some free passes against Bello on Saturday. The Red Sox righty is averaging over two walks per game and 4.2 per nine innings in 2025. 

Red Sox vs. Giants Prediction and Pick

Earlier on Saturday, I shared in SI Betting’s best MLB bets column – Walk-Off Wagers – why the OVER is the bet to make in this matchup on Saturday afternoon:

The Boston Red Sox and San Francisco Giants combined for 12 runs in their series opener on Friday, and I think we could be in line for another high-scoring affair on Saturday afternoon.

Boston will have Bryan Bello on the mound against San Francisco’s Landen Roupp, and neither of these starters gives me a ton of confidence that this will be a pitcher’s duel. 

Even though Bello has allowed three or fewer earned runs in five straight starts, his advanced numbers this season are terrible:

• 4.84 xERA (15th percentile)
• .281 xBAA (13th percentile)
• 17.3% strikeout percentage (16th percentile)

Overall, Bello still has a 3.49 ERA and a 4.27 Fielding Independent Pitching, allowing at least three runs in five of his 11 outings.

On the Giants side, Roupp has an expected ERA of 3.85 this season, and he’s struggled in his last two starts, allowing nine hits and nine runs in just 7.2 innings of work.

Boston has scored the sixth-most runs in MLB this season, so I wouldn’t be shocked to see it get to the young righty on Saturday. This total (set at 8) is a little too low for my liking in Game 2 of this three-game set. 

Pick: OVER 8 (-103 at DraftKings)

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Odds refresh periodically and are subject to change.

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