The Seattle Mariners and Arizona Diamondbacks close out their three-game interleague series on June 11, 2025, at Chase Field in a matchup that pits one of the American League’s most balanced teams against a National League club still searching for stability. The Mariners, who currently sit atop the AL West with a 25–19 record, enter the finale looking to secure another series victory and continue their strong midseason pace. Built around elite starting pitching, power-hitting from the middle of the lineup, and a deep bullpen, Seattle has quickly established itself as a playoff-caliber team capable of winning tight games or slugfests. Their 3.78 team ERA ranks 11th in the league, and their 61 home runs place them sixth, underscoring the club’s two-way efficiency. Cal Raleigh has emerged as one of the league’s premier power-hitting catchers with 15 homers already, while Julio Rodríguez and Ty France continue to deliver timely hits and steady defense. The Mariners’ ability to cover the spread—winning 28 of their last 45 ATS matchups—speaks to their consistency, particularly when traveling. Their lineup is built to capitalize on mistakes, and they’ve done a commendable job manufacturing runs even when the long ball isn’t flying. On the other side, the Diamondbacks are 14–13, holding onto fourth place in a highly competitive NL West.

Despite an underwhelming stretch, Arizona has the offensive firepower to compete, thanks to standout performances from Corbin Carroll, who leads the team with 35 hits, and Eugenio Suárez, who’s contributed 10 home runs. The issue has largely been pitching, with ace Zac Gallen struggling to replicate his prior dominance, as evidenced by his 5.15 ERA across 80.1 innings. The Diamondbacks’ bullpen has also faltered at times, unable to close out games with the same precision that carried them during last season’s playoff run. Statistically, Arizona has only covered in 14 of its last 33 games, reflecting inconsistency on both sides of the ball, especially at home. They’ve been outplayed in four of their last six meetings against Seattle, and unless their arms find a way to limit big innings early, they could be on the verge of dropping another home series. That said, the offense is dangerous when locked in, and if they can get early runs on the board, it could flip momentum quickly. Wednesday’s finale offers more than just a potential series win for Seattle—it’s a test of their ability to dominate winnable games, while for Arizona, it’s a chance to recalibrate and avoid letting a homestand slip away. The outcome may hinge on which starting pitcher can navigate the first five innings without a blowup, and whether either bullpen can avoid the late-inning breakdowns that have defined recent games. With both teams possessing the ability to change the game with one swing, this finale could feature plenty of fireworks, but Seattle’s edge in pitching and execution gives them the upper hand entering what should be a competitive and potentially pivotal interleague showdown.