Kansas City Royals vs
Seattle MarinersPredictions & Preview

George Kirby's Strong Pitching Performance Leads Seattle Mariners to Victory Against Kansas City Royals

On Monday, June 30, 2025, the Kansas City Royals will face off against the Seattle Mariners in an American League matchup at T-Mobile Park in Seattle, Washington. This will be the first meeting between the two teams this season, kicking off a four-game series. Last year, they split a six-game set, with each team winning a three-game home series. The Mariners are currently listed as -145 moneyline favorites with a total of 7.5 runs. Michael Wacha (3.33 ERA) will start for the Royals, while George Kirby (5.4 ERA) is set to start for the Mariners. Seattle opened as -158 favorites and the line has remained steady. Stay tuned for updates and more MLB picks for Monday's slate. The first pitch is scheduled for 9:40 PM ET.

Betting Odds

• Moneyline: Royals +139 | Mariners -158
• Spread: Royals +1.5 (-165) | Mariners -1.5 (+141)
• Total: Over/Under 7.5 (-110)
• Based on the moneyline, the implied probability that Seattle will win straight-up is 61%.

Kansas City vs Seattle Stats

Kansas City Royals

On Sunday, the Kansas City Royals visited the Los Angeles Dodgers for a rubber match of a three-game series. The Royals have had two six-game losing streaks this month but managed to snap one by beating the Dodgers 9-5 last Saturday. Kansas City is currently 3.5 games behind the final wild card spot in the American League. Over the past few weeks, the Royals have struggled offensively and their bullpen has a 3.86 ERA. Michael Wacha will be pitching for the Royals on Monday night, with a 4-7 record, 3.33 ERA in 16 starts this season. Wacha has a 2-3 record with a 5.59 ERA in eight career starts against the Seattle Mariners. The Royals are ranked 30th in offense, 3rd in defense, and have a record of 39-44 this season, with a power ranking of 27.

Seattle Mariners Analysis

The Seattle Mariners faced the Texas Rangers in a three-game series over the weekend, winning one game in extra innings but ultimately losing the series. The Mariners currently hold the final wild card spot in the American League, one game ahead of the Los Angeles Angels. The team has been hitting well and their bullpen has been strong in recent weeks. George Kirby will be starting for the Mariners in their upcoming game against the Kansas City Royals, with a previous record of 1-0 with a 2.25 ERA against them. The Mariners have a power ranking of 7 and rank 11th in offense, scoring an average of 4.59 runs per game. Kansas City has previously gone 1-2 in their last three matchups against Seattle.

George Kirby's Return Sparks Mariners' Favoritism Against Struggling Royals

George Kirby has shown steady improvement since returning from the injured list at the beginning of the season. In the month of June, he has maintained a solid 3.54 ERA and 3.59 FIP. With a strong track record against the Royals, the Mariners are favorited to win this upcoming game. On the other hand, Michael Wacha has struggled with a 4.63 ERA and 4.16 FIP in June. The Mariners have performed well against right-handed pitchers in recent games, boasting a .789 OPS and 126 wRC+. In contrast, the Royals have struggled against righties, with a .685 OPS and 88 wRC+ in the last 10 days. Additionally, the Mariners bullpen has been performing exceptionally lately.

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