Karen's annual ex-M's playoff post

Here is the 2026 version of the Former Seattle Mariners Playing for Other Teams in the Playoffs post, by popular demand from one Karen A. As I write this, ten of twelve (ugh, twelve) postseason teams have been determined, with the hapless American League West entrant and the final National League Wild Card slot still unclaimed—we could get the Houston Astros or Texas Rangers in the former, the Philadelphia Phillies or Arizona Diamondbacks in the latter.

All told, we have 12 former M's in the mix this year, not counting those final two spots. Or 14 if you count the maybes.

To wit:

Tampa Bay Rays (AL East champs): 2

• Ben Williamson (IF): Traded this past offseason from Seattle, Williamson looked like he was going to be the future long-term third baseman for the M's. An excellent defender, his bat was a work in progress as he was, as so many Mariner players have been, promoted too soon from the minors. But, when the M's went looking for lineup help they struck a complicated three-team deal that got them infielder Brendan Donovan but cost them Williamson plus two minor-leaguers. In the short term, the deal has been a bust for both sides, as both Williamson and Donovan spent most of the season on the injured list, but maybe Williamson has the last laugh as his team's in the postseason and Donovan's is, well, not. In about a third of a season's worth of at-bats, Williamson batted a paltry .239/.304/.320 while playing second base and shortstop. He also pitched in five blowout games, giving up two runs on five hits in five innings.
• Casey Legumina (RHP): This guy appeared in 56 games for Seattle in 2025 and ’26 before being shipped off to west Florida for a prospect (Ty Cummings). He's been a better grade of middling for the Rays than he was here, pitching middle and mopup relief.

New York Yankees (AL Wild Card 1): 1

• José Caballero (IF): José was a pretty decent on-base guy with speed off the bench for the M's in 2023. Since then.he's suited up for the Rays and then the Yankees, winning two stolen base crowns with totals that would by mercilessly mocked by Rickey Henderson (44 and 49). This year he's added some pop (14 homers) but dropped 50 points in his on-base percentage.

Boston red Sox (AL Wild Card 2): 0

Cleveland Guardians (AL Central champs OR AL Wild Card 3): 2

• Matt Festa (RHP): Festa broke in with the M's in 2018, missed a couple of years due to Tommy John surgery, then was let go in 2023. He split the next year between the Mets and Rangers, then Texas traded him to Cleveland for the humiliating return of "cash considerations." He's been OK for the Guardians, providing them a decent middle relief option.
• Shawn Armstrong (RHP): Fairly impressive in 14 games as a Mariner in 2018, Armstrong was lost to Baltimore in a waiver claim in early ’19. He was terrible for the Orioles, who dumped him in ’21, and has put up schizophrenic numbers with the Marlins, Rays again, Cardinals, Cubs, and Rangers before landing in Cleveland this year. He's not to be feared.

Chicago White Sox (AL Central champs OR AL Wild Card 3): 1-ish

• Luis Castillo (RHP): "The Rock" has been very hittable since his trade to the Windy City a couple months back. He's given up a whopping 30 runs (29 earned) in 31 innings with the palehose and was relegated to the bullpen after six starts. He's not eligible for either the Wild Card or Division Series rounds thanks to a late placement on the injured list with "shoulder impingement."

Milwaukee Brewers (NL Central champs): 1

• Jake Bauers (1B/OF): A lackluster bench bat for the M's in part of the 2021 campaign, Bauers continued to be nothing special for the Yankees and then Milwaukee, but this year he's come into his own as an everyday player. In ’26 he led the NL in on-base and had more than 25 homers.

Los Angeles Dodgers (NL West champs): 2

• Teoscar Hernández (OF): A fave in Seattle in 2023, Teo signed as a free agent with LA the next season and has been fairly steady for them ever since. He didn't hit as many homers as he's used to this season, but at 33 he's still capable of the big hit now and again.
• Edwin Díaz (RHP): Yet another big-name free-agent signing this past offseason, Díaz has been a bit of a bust as a Dodger. Injured most of the first half, he returned after the All-Star break to post an ERA close to 9.00 in 13 appearances.

Atlanta Braves (NL East champs): 1-ish

• Rowdy Tellez (1B): Rowdy was a Mariner for half a season in 2025, and aside from a couple of timely home runs couldn't really hit his way out of a paper bag. After getting released he hooked up with the Rangers and was a bit better, then this season signed a deal with Atlanta that saw him spend almost the whole year in Triple-A. Not currently on the Atlanta roster, it's conceivable that Tellez could join the team as an injury substitution if necessary.

Chicago Cubs (NL Wild Card 1 or 2): 2

• Matthew Boyd (LHP): Impressive in a short stay in Seattle in 2022, Boyd was an All-Star last year and has been consistently decent when healthy this year, going 10-5 with a sub-4.00 ERA in 22 starts.
• Trent Thornton (RHP): A solid reliever for 2½ seasons in Seattle, he's served the same role with the Cubs this year in between stints on the injured list. He's there now recovering from a sprained ankle, and thus isn't likely to be on the active roster for the WildCard series. He might be activated should the Cubs advance, though.

San Diego Padres (NL Wild Card 1 or 2): 2

• Ty France (IF): After being shipped off to the Reds in the waning days of Scott Servais' reign with Seattle, in a sort of punishment for doing what was asked of him by a terrible hitting coach, it took a bit for Ty to remember he was an All-Star. Signing back with his original team before this season, he hit his way into the starting lineup and got back to being Ty France again. Since the All-Star break he's played like you'd expect Ty France to play, batting .319/.391/.518 in 61 games.
• Robbie Ray (LHP): Ray was traded to the Padres at this year's trade deadline and has been just OK for his new club (3-2, 5.02 ERA in 9 starts). He was with the M's for two injury-plagued seasons in 2022and ’23.

If the Astros get in, they have Taylor Trammell. The Rangers have no one at this point. As for the Phillies, Dylan Moore is in their minor league system, where he's been stinking it up in Triple-A, so we won't see him. Arizona has the great Ketel Marte, who's had a bad year by his standards but it still has All-Star talent. They had Carlos Santana, who was released, and Tyler Locklear is on their 60-day injured list.

Playoffs start on Tuesday with the Wild Card round.