Mariners vs Royals Prediction, Odds, Moneyline, Spread & Over/Under for June 30

Odds updated as of 10:11 a.m.

The Seattle Mariners are among the MLB teams in action on Monday, versus the Kansas City Royals.

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

Mariners vs Royals Game Info

• Seattle Mariners (43-40) vs. Kansas City Royals (39-45)
• Date: Monday, June 30, 2025
• Time: 9:40 p.m. ET
• Venue: T-Mobile Park -- Seattle, Washington
• Coverage: ROOT Sports NW and FDSKC

Mariners vs Royals Odds & Moneyline

• All MLB odds, betting lines and prop bets are available on FanDuel Sportsbook.
• Moneyline: SEA: (-162) | KC: (+136)
• Spread: SEA: -1.5 (+136) | KC: +1.5 (-164)
• Total: 7.5 -- Over: (-100) | Under: (-122)

Mariners vs Royals Probable Starting Pitchers

Probable Pitchers: George Kirby (Mariners) - 1-4, 5.40 ERA vs Michael Wacha (Royals) - 4-7, 3.33 ERA

The Mariners will look to George Kirby (1-4) against the Royals and Michael Wacha (4-7). Kirby and his team have a record of 1-6-0 against the spread when he starts. When Kirby starts a game and his team is the favorite on the moneyline, they have a record of 2-3. The Royals have an 8-8-0 ATS record in Wacha's 16 starts with a set spread. The Royals have been the underdog on the moneyline in 10 of Wacha's starts this season, and they went 6-4 in those games.

Mariners vs Royals Prediction & Pick

All MLB win probability predictions and picks are according to numberFire.
Prediction: Mariners win (56.2%)

Mariners vs Royals Moneyline

• Looking at the moneyline for Royals-Mariners, Kansas City is the underdog at +136, and Seattle is -162 playing at home.

Mariners vs Royals Spread

• The Mariners are hosting the Royals and are favored by 1.5 runs on the spread. The Mariners are +136 to cover the runline, with the Royals being -164.

Mariners vs Royals Over/Under

• The over/under for the Mariners versus Royals game on June 30 has been set at 7.5, with -100 odds on the over and -122 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 51 games this year and have walked away with the win 28 times (54.9%) in those games.
• This season Seattle has been victorious seven times in 14 chances when named as a favorite of at least -162 on the moneyline.
• Contests with the Mariners have gone over the total set by bookmakers in 44 of 81 chances this season.
• The Mariners have an against the spread record of 35-46-0 in 81 games with a line this season.
• The Royals have gone 24-27 in games they were listed as the moneyline underdog (winning 47.1% of those games).
• Kansas City has a record of 5-4 in games it has played as a moneyline underdog with odds of +136 or longer (55.6%).
• The Royals have played in 83 games with a set over/under, and have combined with opponents to go over the total 31 times (31-50-2).
• The Royals have a 43-40-0 record ATS this season.

Mariners Player Leaders

• Cal Raleigh has 84 hits and an OBP of .388, both of which lead Seattle hitters this season. He has a .275 batting average and a slugging percentage of .643.
• Among all qualified batters in the majors, he is 48th in batting average, eighth in on-base percentage, and second in slugging.
• Raleigh has hit safely in three straight games. In his last five games he is hitting .176 with a double and seven walks.
• Julio Rodriguez leads Seattle in slugging percentage (.409) thanks to 26 extra-base hits. He's batting .259 with an on-base percentage of .317.
• He is 74th in batting average, 103rd in on-base percentage and 97th in slugging in MLB.
• Rodriguez takes a three-game streak with at least one hit into this contest. In his last five games he is hitting .364 with a double and an RBI.
• J.P. Crawford has collected 81 base hits, an OBP of .386 and a slugging percentage of .373 this season.
• Randy Arozarena has eight home runs, 33 RBI and a batting average of .241 this season.
• Arozarena takes a two-game hitting streak into this game. In his last five games he is hitting .300 with a double, two walks and two RBIs.

Royals Player Leaders

• Bobby Witt Jr. leads the Royals with 94 hits. He's batting .285 and slugging .491 with an on-base percentage of .338.
• Including all the qualified hitters in the majors, his batting average ranks 30th, his on-base percentage is 64th, and he is 28th in slugging.
• Witt enters this game on a three-game hitting streak. During his last five outings he is hitting .318 with three doubles, a home run and three RBIs.
• Maikel Garcia has a .371 on-base percentage while slugging .485. Both are team-highs. He has a batting average of .314.
• Including all qualifying hitters, he is eighth in batting average, 22nd in on-base percentage and 33rd in slugging percentage.
• Vinnie Pasquantino is batting .270 with nine doubles, a triple, 12 home runs and 25 walks.
• Jonathan India is batting .246 with 16 doubles, four home runs and 30 walks.

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