Royals vs Mariners Prediction, Odds, Moneyline, Spread & Over/Under for Sept. 17

Odds updated as of 2:14 a.m.

Wednesday's slate in the MLB includes a matchup between the Kansas City Royals and the Seattle Mariners.

Here's everything you need to know before checking out today's MLB odds and spreads on FanDuel Sportsbook.

Royals vs Mariners Game Info

• Kansas City Royals (75-76) vs. Seattle Mariners (83-68)
• Date: Wednesday, September 17, 2025
• Time: 7:40 p.m. ET
• Venue: Kauffman Stadium -- Kansas City, Missouri
• Coverage: FDSKC and ROOT Sports NW

Royals vs Mariners Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: KC: (-112) | SEA: (-104)
• Spread: KC: +1.5 (-182) | SEA: -1.5 (+150)
• Total: 8.5 -- Over: (-110) | Under: (-110)

Royals vs Mariners Probable Starting Pitchers

Probable Pitchers: Cole Ragans (Royals) - 2-3, 5.18 ERA vs Bryce Miller (Mariners) - 4-5, 5.59 ERA

The probable starters are Cole Ragans (2-3) for the Royals and Bryce Miller (4-5) for the Mariners. Ragans and his team are 4-6-0 ATS this season when he starts. Ragans' team has won 50% of his starts when they are favored on the moneyline (4-4). When Miller starts, the Mariners have gone 7-8-0 against the spread. The Mariners have a 2-3 record in Miller's five starts this season when they were the moneyline underdog.

Royals vs Mariners Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Mariners win (51%)

Royals vs Mariners Moneyline

• Looking at the moneyline for Royals-Mariners, Kansas City is the favorite at -112, and Seattle is -104 playing on the road.

Royals vs Mariners Spread

• The Mariners are 1.5-run favorites against the spread for this matchup with the Royals. The Mariners are +150 to cover, while the Royals are -182 to cover as a 1.5-run underdog on the runline.

Royals vs Mariners Over/Under

• The over/under for Royals-Mariners on Sept. 17 is 8.5. The over is -110, and the under is -110.

Bet on Kansas City Royals vs. Seattle Mariners on FanDuel today!

Royals vs Mariners Betting Trends

• The Royals have come away with 35 wins in the 62 contests they have been listed as the favorites in this season.
• Kansas City has a record of 35-27 when favored by -112 or more this year.
• The Royals and their opponents have gone over in 64 of their 149 games with a total set by sportsbooks this season.
• The Royals have an against the spread mark of 72-77-0 in 149 games with a line this season.
• The Mariners have won 47.4% of the games this season they were the underdog on the moneyline (18-20).
• Seattle has an 18-17 record (winning 51.4% of its games) when playing as a moneyline underdog of -104 or longer.
• In the 146 games bookmakers have set an over/under for the Mariners, they have combined with opponents to go over the total 79 times (79-62-5).
• The Mariners have collected a 64-82-0 record against the spread this season (covering 43.8% of the time).

Royals Player Leaders

• Bobby Witt Jr. has 167 hits to go with a slugging percentage of .500, both of which are tops among Kansas City hitters this season. He has a .292 batting average and an on-base percentage of .352.
• Among all qualified hitters, he ranks 12th in batting average, his on-base percentage ranks 34th, and he is 18th in slugging.
• Witt has recorded a base hit in two straight games. During his last five outings he is hitting .211 with a triple, a home run, two walks and two RBIs.
• Maikel Garcia has 160 hits this season and a team-best OBP of .354. He's batting .289 and slugging .458.
• Among qualified batters, his batting average ranks him 15th, his on-base percentage 32nd, and his slugging percentage 51st.
• Vinnie Pasquantino has 151 hits this season and has a slash line of .263/.321/.470.
• Salvador Perez is batting .237 with a .277 OBP and 89 RBI for Kansas City this season.
• Perez heads into this game on a three-game hitting streak. During his last five outings he is batting .273 with three home runs and eight RBIs.

Mariners Player Leaders

• Cal Raleigh has racked up a team-high OBP (.361), and leads the Mariners in hits (137). He's batting .247 and slugging.
• Including all qualifying hitters, he ranks 100th in batting average, while his on-base percentage is 17th and he is third in slugging.
• Raleigh heads into this game on a four-game hitting streak. During his last five outings he is hitting .444 with three doubles, three home runs, five walks and five RBIs.
• Julio Rodriguez leads his team with a .480 slugging percentage. He has a batting average of .271 with an on-base percentage of .323.
• He is 37th in batting average, 87th in on-base percentage and 31st in slugging percentage in MLB.
• Josh Naylor has 26 doubles, a triple, 19 home runs and 46 walks while hitting .283.
• Eugenio Suarez has 25 doubles, 45 home runs and 44 walks while batting .224.

Royals vs Mariners Head to Head

• 9/16/2025: 12-5 SEA (Favorite: Mariners, Spread: -1.5, Total: 8.5, Favorite Moneyline: -136, Underdog Moneyline: +116)
• 7/3/2025: 3-2 KC (Favorite: Mariners, Spread: -1.5, Total: 7.5, Favorite Moneyline: -120, Underdog Moneyline: +102)
• 7/2/2025: 3-2 SEA (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -166, Underdog Moneyline: +140)
• 7/1/2025: 6-3 KC (Favorite: Mariners, Spread: -1.5, Total: 8, Favorite Moneyline: -138, Underdog Moneyline: +118)
• 6/30/2025: 6-2 SEA (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -164, Underdog Moneyline: +138)
• 6/9/2024: 6-5 SEA (Favorite: Royals, Spread: -1.5, Total: 7.5, Favorite Moneyline: -136, Underdog Moneyline: +116)
• 6/8/2024: 8-4 KC (Favorite: Mariners, Spread: -1.5, Total: 8.5, Favorite Moneyline: -134, Underdog Moneyline: +114)
• 6/7/2024: 10-9 KC (Favorite: Mariners, Spread: -1.5, Total: 9, Favorite Moneyline: -122, Underdog Moneyline: +104)
• 5/15/2024: 4-2 SEA (Favorite: Mariners, Spread: -1.5, Total: 8, Favorite Moneyline: -142, Underdog Moneyline: +120)
• 5/14/2024: 4-2 KC (Favorite: Mariners, Spread: -1.5, Total: 7.5, Favorite Moneyline: -164, Underdog Moneyline: +138)

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