• The Mariners are -155 favorites vs the Diamondbacks
• Diamondbacks vs Mariners Over / Under today: 7.5 Runs
• Diamondbacks / Mariners TV Channel: MRTV | DBTV

The Arizona Diamondbacks (+125) visit T-Mobile Park to take on the Seattle Mariners (-155) on May 31, 2026. First pitch is scheduled for 4:10 pm in Seattle, WA.

This season, the Diamondbacks are 31-26 against the spread (ATS), while the Mariners are 23-36 ATS.

Diamondbacks vs Mariners Starting Pitchers Today:

• Diamondbacks starting pitcher: Merrill Kelly 5-3, 5.22 ERA
• Mariners starting pitcher: Bryce Miller 1-0, 2.25 ERA

Diamondbacks vs. Mariners Odds, Run Line, Over/Under & Moneyline

Diamondbacks vs Mariners Prediction for Today’s Game

Based on recent trends the model predicts the Mariners will win Sunday‘s MLB game with 54.7% confidence, factoring in game simulations, recent player performances, starting pitchers and injuries.

Bet now on Diamondbacks vs Mariners and all games with BetMGM

We’ve highlighted some favorite MLB player prop bets for Diamondbacks players for Sunday‘s game, looking at profitable historical betting trends:

Best Diamondbacks Player Prop Bets Today:

• Adrian Del Castillo has hit the Runs Under in 18 of his last 20 games (+12.90 Units / 31% ROI)
• Gabriel Moreno has hit the Home Runs Over in 2 of his last 9 games (+12.00 Units / 133% ROI)
• Corbin Carroll has hit the RBIs Under in 17 of his last 20 away games (+11.95 Units / 27% ROI)
• Ildemaro Vargas has hit the Hits Runs and RBIs Over in 18 of his last 25 away games (+11.00 Units / 40% ROI)
• Ketel Marte has hit the Total Bases Over in 15 of his last 20 games (+10.95 Units / 51% ROI)

And here are some favorite MLB player prop bets for Mariners players for Sunday‘s game, looking at profitable historical betting trends:

Best Mariners Player Prop Best Bets Today:

• J.P. Crawford has hit the Home Runs Over in 4 of his last 9 games at home (+29.50 Units / 328% ROI)
• Cole Young has hit the Runs Under in 22 of his last 25 games (+16.45 Units / 32% ROI)
• Randy Arozarena has hit the Walks Under in 20 of his last 25 games (+10.15 Units / 21% ROI)
• Julio Rodriguez has hit the Hits Over in 18 of his last 25 games at home (+9.70 Units / 20% ROI)
• Josh Naylor has hit the Singles Over in 18 of his last 25 games (+9.40 Units / 31% ROI)

Diamondbacks Best Bets Today:

• The Arizona Diamondbacks have hit the Team Total Over in 33 of their last 50 away games (+13.90 Units / 24% ROI)
• The Arizona Diamondbacks have hit the 1st Five Innings (F5) Team Total Under in 24 of their last 35 games (+12.70 Units / 31% ROI)
• The Arizona Diamondbacks have hit the Moneyline in 14 of their last 20 games (+6.40 Units / 24% ROI)
• The Arizona Diamondbacks have hit the Game Total Over in 25 of their last 45 away games (+6.40 Units / 13% ROI)
• The Arizona Diamondbacks have covered the Run Line in 29 of their last 50 games (+4.35 Units / 6% ROI)

Mariners Best Bets Today:

• The Seattle Mariners have covered the 1st Five Innings (F5) Run Line in 14 of their last 22 games (+5.65 Units / 23% ROI)
• The Seattle Mariners have hit the 1st Five Innings (F5) Team Total Under in 21 of their last 35 games (+5.15 Units / 12% ROI)
• The Seattle Mariners have hit the 1st Five Innings (F5) Moneyline in 14 of their last 22 games (+5.10 Units / 16% ROI)
• The Seattle Mariners have hit the Moneyline in their last 5 games (+5.00 Units / 80% ROI)
• The Seattle Mariners have covered the Run Line in 4 of their last 5 games (+4.80 Units / 96% ROI)

Diamondbacks Against the Spread (ATS) Record

Against the spread this season, the Diamondbacks are 34-22 against the Run Line (+6.9 Units / 8.71% ROI).

• 31-26 when betting on the Moneyline for +4.55 Units / 6.77% ROI
• 28-26 when betting on the total runs Over for -0.5 Units / -0.79% ROI
• 26-28 when betting on the total runs Under for -4.6 Units / -7.35% ROI

Mariners Against the Spread (ATS) Record

Against the spread this season, the Mariners are 23-36 against the Run Line (-7.15 Units / -11.55% ROI).

• 30-29 when betting on the Moneyline for -9.25 Units / -11.27% ROI
• 27-30 when betting on the total runs Over for -5.95 Units / -9.15% ROI
• 30-27 when betting on the total runs Under for +0.3 Units / 0.46% ROI

Mariners vs Diamondbacks Home Run Prop Bets Today

Mariners vs Diamondbacks Total Hits Prop Bets Today

Mariners vs Diamondbacks Strikeout Prop Bets Today

Diamondbacks Keys to the Game vs. the Mariners

The Diamondbacks are 5-17 (.227) when trailing entering the 7th inning this season — 3rd best in MLB; League Avg: .141.

The Diamondbacks are just 84-22 (.792) when leading entering the 7th inning since the 2025 season — 3rd lowest in MLB; League Avg: .871.

The Diamondbacks are 7-86 (.075) when trailing entering the 9th inning since the 2025 season — 3rd best in MLB; League Avg: .046.

The Diamondbacks were just 67-7 (.905) when leading entering the 9th inning in the 2025 season — 2nd lowest in MLB; League Avg: .956.

Mariners Keys to the Game vs. the Diamondbacks

The Mariners are 6-84 (.067) when trailing entering the 9th inning since the 2025 season — 4th best in MLB; League Avg: .046.

The Mariners are 25-15 (.625) when tied entering the 7th inning since the 2025 season — 4th best in MLB; League Avg: .500.

The Mariners were 9-55 (.141) when trailing entering the 8th inning in the 2025 season — 3rd best in MLB; League Avg: .090.

The Mariners were 12-55 (.179) when trailing entering the 7th inning in the 2025 season — 3rd best in MLB; League Avg: .124.

Diamondbacks Hitting Stats & Trends

Diamondbacks hitters have struck out in just 17% of their PA’s against LHP this season — 2nd best in MLB.

Diamondbacks hitters have an OPS of .792 (593 PA’s) against LHP this season — 2nd best in MLB.

The Diamondbacks are batting .281 against LHP this season — best in MLB.

Diamondbacks hitters are slugging .499 with runners in scoring position this season — best in MLB.

Mariners Hitting Stats & Trends

Mariners hitters are slugging just .329 against LHP this season — tied for 2nd lowest in MLB.

Mariners hitters have an OBP of just .285 (661 PA’s) against LHP this season — lowest in MLB.

Mariners hitters have an OPS of just .614 (661 PA’s) against LHP this season — lowest in MLB.

The Mariners are batting just .204 against LHP this season — lowest in MLB.

Diamondbacks Pitching Stats & Trends

Diamondbacks pitchers have a strikeout rate of just 19% this season — 2nd lowest in MLB.

Diamondbacks pitchers have walked 6% of batters when facing the leadoff batter in the inning this season — 2nd best in MLB.

Diamondbacks pitchers have walked 8% of batters this season — tied for 3rd best in MLB.

Diamondbacks pitchers have a strikeout rate of just 39% with two-strikes this season — 5th lowest in MLB.

Mariners Pitching Stats & Trends

Mariners pitchers have a first-pitch strike rate of 67% this season — highest in MLB.

Mariners pitchers have walked 7% of batters this season — tied for best in MLB.

Mariners pitchers have walked 6% of batters when facing the leadoff batter in the inning this season — 3rd best in MLB.

Mariners pitchers have thrown at least two strikes in their first three pitches to 69% of opposing batters this season — highest in MLB.

More MLB Reading:

• Home Run Predictions Today
• Best NRFI Bets Today
• Strikeout Props Today
• MLB Starting Pitchers Today

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