Mariners' Magic Number To Clinch Playoff Spot Dropping Despite Guardians Surge

A division title would be fantastic, but the Seattle Mariners have to make sure, first and foremost, that they lock up a playoff spot.

There are a lot of things happening around the American League right now that add context to the Mariners' chances. The Houston Astros and Cleveland Guardians are surging. The Detroit Tigers and Boston Red Sox are suddenly in peril. And the three-game showdown with the Astros in Houston this weekend will clear up a lot of the uncertainty, for better or worse.

So, after Seattle picked up a 2-0 win over the Kansas City Royals on Thursday, here are the various magic numbers, playoff scenarios, and reasons for hope and concern.

Mariners' playoff magic number: 7

Sep 16, 2025; Kansas City, Missouri, USA; The Seattle Mariners celebrate a win against the Kansas City Royals at Kauffman Stadium. Mandatory Credit: Scott Sewell-Imagn Images | Scott Sewell-Imagn Images

The Guardians (81-71), winners of 12 of their last 13 games, have become the No. 1 threat to every AL team hoping to retain its playoff position. They're 2 1/2 games back of Houston and Seattle (both 84-69), and 1 1/2 back of Boston (83-70), which has won just one series since star rookie Roman Anthony hit the injured list on Sept. 3.

Fortunately, the Mariners own the tiebreaker over the Guardians, who play four games in three days on the road against the Minnesota Twins this weekend. That makes Seattle's magic number to clinch a playoff spot seven entering play on Friday.

While it's not a guarantee by any means that the Mariners finish ahead of the red-hot Guardians, especially if they stumble in Houston this weekend, they would also make the playoffs if they finished ahead of Boston, or for that matter, the Detroit Tigers (85-68), who were swept by Cleveland on their home field this week and play the Guardians three more times on the road next week.

Staying on that wave, the Mariners took the season series against the Tigers this season, so if they win the AL West, the Tigers win the AL Central, and the Mariners outpace Detroit by one game the rest of the way, they'd have the No. 2 seed and a bye straight to the Division Series.

That's a lot to digest, but for now, the Mariners just have to forget all the scenarios and focus on winning the series against Houston this weekend. Take care of business, and the rest will sort itself out in Seattle's favor.

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