The Oakland Athletics and Seattle Mariners meet on August 23, 2025, at T-Mobile Park in a divisional matchup that feels far more intriguing than it might have just a few months ago, with Oakland emerging as one of baseball’s more surprising post-All-Star break stories and Seattle suddenly facing pressure after stumbling through a rough stretch. The Mariners enter as heavy favorites on the moneyline around –186, backed by a strong home-field record and their standing in the AL West race, but they are also coming off a brutal 2–7 road trip that has magnified their offensive inconsistencies and put their Wild Card hopes in jeopardy. Meanwhile, Oakland, written off earlier in the year, has gone 18–13 since the break and surged offensively behind breakout stars like Nick Kurtz, who has been on an absolute tear hitting well over .400 with massive slugging numbers, Shea Langeliers, who has powered his way into the home run leaderboard with 16 long balls since mid-July, and Tyler Soderstrom, whose 213 wRC+ this month has helped turn the A’s into one of the most dangerous lineups in August. This makes the Athletics a live underdog and a team that bettors have started to watch closely, particularly given Seattle’s recent struggles and Oakland’s ability to score in bunches.

On the pitching side, the A’s send top prospect Luis Morales to the mound, a right-hander with electric velocity and swing-and-miss stuff who impressed in his last outing with over five innings of one-run ball despite some control issues, and his development will be a key storyline as Oakland looks to continue proving its rebuild is ahead of schedule. Seattle will counter with Bryan Woo, a talented young arm who has shown flashes of brilliance but has also dealt with stretches of inconsistency, and his ability to get ahead early and limit walks will be crucial against an Athletics lineup that has been punishing mistakes. For the Mariners, playing at home is a significant advantage—they are a far better team in Seattle, where the crowd energy and familiarity often lift their performance—but the weight of their recent slump could add pressure if they fall behind early. Offensively, they will need veterans like Julio Rodríguez and Cal Raleigh to deliver against Morales, while hoping their bullpen avoids the overwork that plagued them during the road trip. For the Athletics, the key will be extending at-bats, forcing Woo to elevate his pitch count, and then attacking Seattle’s bullpen late while relying on their red-hot hitters to continue carrying the load. From a betting perspective, the Mariners’ status as favorites makes sense, but the Athletics’ offensive momentum since the break makes them an appealing ATS option and a dangerous underdog capable of pulling the upset if their young pitching holds up. Ultimately, this game is a test of Seattle’s resilience in the face of adversity and Oakland’s legitimacy as more than just a post-break spoiler, and the outcome may hinge less on raw talent and more on which team executes better in high-leverage moments. If the Mariners rediscover their rhythm at home, they should take care of business, but if Oakland’s bats stay as hot as they’ve been, the A’s could easily walk out of Seattle with another statement win.