The Seattle Mariners host the Houston Astros on Wednesday, September 23, 2026, at T-Mobile Park for a 10:10 p.m. ET first pitch, with the game airing nationally on ESPN and the ESPN App. George Kirby gets the ball for Seattle, squaring off against Houston's Ethan Pecko in what figures to be a pivotal late-regular-season matchup between two AL West rivals. With September winding down and standings implications still very much alive, every game between these two franchises carries weight.

George Kirby vs. Ethan Pecko: Starting Pitcher Breakdown

Kirby is the anchor of this Seattle rotation, a strike-throwing right-hander who consistently limits walks and generates contact on his terms. He gives Seattle exactly what you want from a Wednesday night home start — efficiency, length, and the ability to keep a dangerous lineup in check. The Mariners need innings from him, and Kirby is the kind of pitcher you trust to deliver them.

Pecko is the less-established name in this matchup. The Houston right-hander will be facing a Seattle lineup that has enough bats to make any starter uncomfortable at T-Mobile Park. This is a spot where the Mariners should look to grind at-bats and make Pecko work deep into counts.

Seattle Mariners Starting Lineup

• J.P. Crawford — SS
• Randy Arozarena — LF
• Dominic Canzone — DH
• Cal Raleigh — C
• Julio Rodríguez — CF
• Josh Naylor — 1B
• Cole Young — 2B
• Lazaro Montes — RF
• Weston Wilson — 3B

Keys to Watch for Seattle

Cal Raleigh in the Cleanup Spot

Raleigh batting fourth is a straightforward statement of trust from the Seattle dugout. He has the power profile to punish a pitcher who falls behind in the count, and against a starter like Pecko whose sample in the majors is limited, that patience-and-power combination could be decisive.

Julio Rodríguez Batting Fifth

J-Rod hitting fifth rather than higher in the order is worth noting. However the lineup construction shakes out, Rodríguez remains one of the most dangerous athletes in the Seattle order — a hitter who can change a game with his legs and his bat. Keep an eye on how Pecko tries to navigate that part of the lineup.

Kirby's Strike Zone Command

The Mariners win this game if Kirby is Kirby — attacking the zone, avoiding deep counts, and turning lineouts and groundouts into quick innings. If Houston makes him work, the bullpen will face pressure. The margin for error gets smaller late in the regular season.

Broadcast Information

Wednesday's game can be seen on ESPN and the ESPN App. Radio coverage is available in English on Seattle Sports 710 AM and in Spanish on KLTN-TUDN 102.9 FM.

Prediction

Kirby at home against a pitcher making his case for a roster spot gives Seattle a genuine edge. The middle of this Mariners lineup — Raleigh, Rodríguez, Naylor — is capable of doing real damage against an unfamiliar arm. Expect Kirby to go six-plus innings, the offense to generate enough, and Seattle to take this one. Mariners 4, Astros 2.