This series in Houston has been circled on the schedule since the beginning of the season. If the Mariners had any designs on winning the AL West for the first time since 2001, this series always felt like the inflection point that would decide the division. The tension continued to ratchet up as the season wore on as these two teams battled back and forth in the standings. It’s fitting that they’re entering this fateful series tied in the standings with everything to play for. The winner of the series will
secure the all-important tiebreaker, giving them a huge advantage to hold onto the division lead during the final week of the season. The actual postseason doesn’t begin for another week and a half, but the M’s might as well treat this three-game set as a round-zero playoff series.
While the Mariners have surged during the second half of the season, the Astros have sort of limped to this point. Houston is a game under .500 since the All-Star break and their roster is missing a ton of key contributors thanks to a rash of injuries. The biggest blow occurred on Monday when Yordan Alvarez sprained his ankle crossing home plate less than a month after he was activated from a nearly four-month long IL stint. Their pitching staff has also been ravaged by injuries with six starters on the IL with significant injuries and closer Josh Hader slidelined with a sprained shoulder. The ‘Stros managed to sweep the Rangers earlier this week and have their best starters lined up to face the Mariners. They may be weakened, but they’re still a dangerous and desperate foe.
Beyond all the injuries, the biggest problem the Astros have faced has been an inconsistent and shallow offense. Just five of their regulars have a wRC+ over 100 during the second half, and trade deadline acquisitions Jesús Sánchez and Ramón Urías have been pretty significant disappointments. Their big deadline deal was a reunion with Carlos Correa and he’s very capably made the transition to third base since returning to his original organization. He leads the team with a 123 wRC+ since the All-Star break.
Probable Pitchers

From a previous series preview:
Hunter Brown was an absolute mess to start last year — his ERA was over nine through his first six starts — but he experimented with adding a sinker to his pitch mix in a May start against the Mariners and that one pitch unlocked his entire repertoire. Over his final 24 starts, he ran a 2.51 ERA and a 3.25 FIP and finally put everything together. His arsenal is deep, featuring six different pitches, but all of his secondary pitches break away from right-handed batters. The sinker gave him a pitch that he could use on the inner half of the plate to keep them honest against his breaking balls. That one pitch helped all of his others to play up, and once he figured out how to utilize his entire arsenal, he thrived.
From a previous series preview:
Framber Valdez turned in another fantastic season last year, earning a seventh place finish in the Cy Young voting, his third straight season with down ballot votes. It’s actually quite impressive how consistent he’s been during this stretch; his excellent strikeout-to-walk ratio has barely budged, his groundball rate is continually excellent, and he hasn’t run into any bad batted ball luck or home run issues. It all starts with his curveball. That breaking ball is one of the best in baseball and continues to give opposing batters fits. Valdez has dabbled with a few versions of his repertoire that included a cutter or four-seamer over the years, but he’s settled on the core trio of pitches that have worked so well for him throughout his career. That kind of consistency makes Valdez a bit underrated, but make no mistake, he’s still one of the best pitchers in the American League.
With all the injuries to the Astros pitching staff, they’ve had to scrape up some unlikely contributors this year. Jason Alexander had a short stay in the big leagues way back in 2022, but he’s bounced around the minor leagues in the three years since and the Astros are his third organization in as many years. The big reason why he’s finally managed to stick in the majors — beyond the necessity of a warm body occupying the fifth starter slot in Houston — is that he finally managed to develop a third pitch to go along with his mediocre sinker-sweeper combo. His changeup has suddenly turned into a pretty fantastic weapon which has made all the difference for his overall success.
The Big Picture:
Thanks to the Astros’ sweep of the Rangers this week, the M’s don’t really need to worry about Texas anymore. The Rangers are four games back with nine to play and will host the Marlins for three this weekend. Maybe the last remaining threat in the Wild Card race is the Guardians who swept the Tigers to run their win streak to seven games. Cleveland has a four-game series this weekend in Minnesota — with a double-header on Saturday — before they clash with the Tigers again next week. The Red Sox lost their series to the Athletics this week and slipped behind Houston and Seattle in the Wild Card standings. Boston travels to Tampa Bay to face the Rays this weekend.