MLB Prop Bets: Seattle Mariners vs Arizona Diamondbacks (May 31, 2026)
The Arizona Diamondbacks (31-26) face the Seattle Mariners (30-29) at T-Mobile Park on Sunday at 4:10pm (ET). Let's take a look at the MLB Prop Bets for the matchup. Merrill Kelly is the probable pitcher for the Diamondbacks, while Bryce Miller is the probable pitcher for the Mariners. The Mariners are favored to win at -156, while the Diamondbacks are at +129. The total runs line is set at 7.5, with OVER at -107 and UNDER at -112.
- The Diamondbacks (-171) have a 34-23 Run Line record this season, while the Mariners (+141) hold a record of 25-34.
- The Diamondbacks have a 26-25-6 O/U record this season (meaning 26 games have gone over the total runs line, 25 have gone under and six have resulted in a push). The Mariners have a 27-30-2 O/U record.
Scoring Insights
- The Diamondbacks are averaging 4.6 runs per game this season (11th in the league). Comparatively, the Mariners are averaging 4.3 (17th).
- In the field, the Diamondbacks are allowing 4.4 runs per game this season (16th in the league), while the Mariners are allowing an average of 3.8 runs (5th).
Let's take a look at how these teams perform in some other key statistical areas.
Batting Insights:
Batting Average
- Looking at their batting averages this season, the Diamondbacks are at .247 (ranking 6th in the Major leagues), while the Mariners are batting .233 (23rd).
Home Runs
- In terms of total home runs this season, the Mariners have hit 74 (7th in the Major Leagues). Meanwhile, the Diamondbacks have managed 49 (26th).
Runs Batted In
- Finally, looking at their runs batted in, the Diamondbacks have recorded 252 RBIs to rank 11th in the MLB this season. Comparatively, the Mariners have recorded 246 RBIs to rank 13th.
Pitching Insights:
Earned Run Average
- The Mariners have an earned run average of 3.51 this season (5th in the Majors), while The Diamondbacks have an ERA of 4.06 (15th).
Strikeouts
- Turning our attention to total strikeouts, the Diamondbacks have recorded 404 this season, ranking 30th in the MLB. Meanwhile, the Mariners rank 10th for total strikeouts, recording 501.
Opponent Batting Average
- Opponents are batting an average of .246 against the Mariners this season (20th in the Major Leagues). Comparatively, the Diamondbacks' opponents are at .241 (17th).
First Innings Moneyline
- Here are their first innings moneyline records in 2026.
| Total | Home | Road | Favorite | Underdog | Neutral | Last 10 | |
|---|---|---|---|---|---|---|---|
| Diamondbacks | 13-15-29 | 7-5-14 | 6-10-13 | 7-3-13 | 6-12-16 | 0-0-2 | 1-2-7 |
| Mariners | 17-14-28 | 11-9-11 | 6-5-17 | 17-13-23 | 0-1-5 | 0-0-0 | 4-1-5 |
Lead After Three Innings
- Here are their records after the first three innings in 2026.
| Total | Home | Road | Favorite | Underdog | Neutral | Last 10 | |
|---|---|---|---|---|---|---|---|
| Diamondbacks | 23-24-10 | 13-6-7 | 9-17-3 | 14-4-5 | 9-20-5 | 1-1-0 | 6-3-1 |
| Mariners | 27-18-14 | 15-10-6 | 12-8-8 | 23-17-13 | 4-1-1 | 0-0-0 | 7-1-2 |
NRFI/YRFI
The NRFI market is paying -115 and the YRFI is paying -115.
- The NRFI is 25-32 in Diamondbacks games this season. The Mariners have a 25-34 NRFI record.
Last Time They Met
The Mariners recorded an upset 5-1 victory over the Diamondbacks at T-Mobile Park yesterday. Julio Rodriguez was unstoppable in that matchup, hitting a home run, a double and recording an RBI.
