Mariners vs Royals Prediction, Odds, Moneyline, Spread & Over/Under for Sept. 16

Odds updated as of 7:12 p.m.

The Seattle Mariners will take on the Kansas City Royals in MLB action on Tuesday.

We've got you covered, in terms of the most important information regarding this game before you take a look at the MLB odds and spreads on FanDuel Sportsbook.

Mariners vs Royals Game Info

• Seattle Mariners (82-68) vs. Kansas City Royals (75-75)
• Date: Tuesday, September 16, 2025
• Time: 7:40 p.m. ET
• Venue: Kauffman Stadium -- Kansas City, Missouri
• Coverage: FDSKC and ROOT Sports NW

Mariners vs Royals Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: SEA: (-136) | KC: (+116)
• Spread: SEA: -1.5 (+116) | KC: +1.5 (-140)
• Total: 8.5 -- Over: (-112) | Under: (-108)

Mariners vs Royals Probable Starting Pitchers

Probable Pitchers: Logan Gilbert (Mariners) - 4-6, 3.54 ERA vs Michael Wacha (Royals) - 9-11, 3.45 ERA

This contest's pitching matchup is set, as the Mariners will send Logan Gilbert (4-6) to the mound, while Michael Wacha (9-11) will get the nod for the Royals. Gilbert's team is 7-14-0 against the spread this season in his starts. Gilbert's team has a record of 12-5 this season when he starts and they are the favorite on the moneyline. The Royals have gone 12-16-0 against the spread when Wacha starts. The Royals have been the moneyline underdog in 17 of Wacha's starts this season, and they went 8-9 in those games.

Mariners vs Royals Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Mariners win (57.2%)

Mariners vs Royals Moneyline

• The Mariners vs Royals moneyline has Seattle as a -136 favorite, while Kansas City is a +116 underdog at home.

Mariners vs Royals Spread

• The Royals are +1.5 on the spread (-140 to cover), and Seattle is +116 to cover the runline.

Mariners vs Royals Over/Under

• The over/under for the Mariners versus Royals contest on Sept. 16 has been set at 8.5, with -112 odds on the over and -108 odds on the under.

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

Mariners vs Royals Betting Trends

• The Mariners have been chosen as favorites in 103 games this year and have walked away with the win 60 times (58.3%) in those games.
• This year Seattle has won 38 of 58 games when listed as at least -136 on the moneyline.
• The Mariners and their opponents have gone over the total this season in 78 of their 145 opportunities.
• The Mariners have posted a record of 63-82-0 against the spread this season.
• The Royals have won 39 of the 86 games they were the moneyline underdog this season (45.3%).
• Kansas City has a 19-22 record (winning 46.3% of its games) when it has played as a moneyline underdog of +116 or longer.
• The Royals have combined with opponents to hit the over on the total 63 times this season for a 63-83-2 record against the over/under.
• The Royals have collected a 72-76-0 record ATS this season (covering 48.6% of the time).

Mariners Player Leaders

• Cal Raleigh has 134 hits and an OBP of .359, both of which rank first among Seattle hitters this season. He has a .244 batting average and a slugging percentage of .577.
• Among qualified hitters in baseball, he is 99th in batting average, 19th in on-base percentage, and third in slugging.
• Raleigh has recorded a base hit in three games in a row. During his last five outings he is batting .375 with two doubles, a home run, eight walks and two RBIs.
• Julio Rodriguez has hit 30 homers this season while driving in 91 runs. He's batting .269 this season and slugging .478 with an on-base percentage of .321.
• Among all qualifying batters, he is 40th in batting average, 93rd in on-base percentage and 32nd in slugging percentage.
• Rodriguez heads into this game looking to extend his five-game hit streak. During his last five outings he is batting .400 with five doubles, three walks and four RBIs.
• Josh Naylor is batting .284 with a .450 slugging percentage and 85 RBI this year.
• Naylor has recorded at least one base hit in two straight games. In his last five games he is hitting .318 with a home run, a walk and six RBIs.
• Eugenio Suarez is batting .226 with a .300 OBP and 109 RBI for Seattle this season.

Royals Player Leaders

• Bobby Witt Jr. has a slugging percentage of .501 and has 166 hits, both team-best numbers for the Royals. He's batting .292 and with an on-base percentage of .350.
• Including all qualifying hitters in the majors, he ranks 12th in batting average, 37th in on-base percentage and 17th in slugging percentage.
• Maikel Garcia has a .355 OBP to lead his team. He has a batting average of .291 while slugging .462.
• Including all qualified players, he ranks 13th in batting average, 29th in on-base percentage and 44th in slugging percentage.
• Vinnie Pasquantino has 27 doubles, a triple, 30 home runs and 45 walks while batting .265.
• Salvador Perez has 34 doubles, 28 home runs and 23 walks while hitting .237.

Mariners vs Royals Head to Head

• 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)
• 5/13/2024: 6-2 SEA (Favorite: Mariners, Spread: -1.5, Total: 7, Favorite Moneyline: -154, Underdog Moneyline: +130)

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