Sep 6, 2025; Cumberland, Georgia, USA; Seattle Mariners pitcher Caleb Ferguson (43) pitches the ball against the Atlanta Braves during the eighth inning at Truist Park. Mandatory Credit: Jordan Godfree-Imagn Images Jordan Godfree-Imagn Images

Reliever Caleb Ferguson Could be an X-Factor for the Mariners in the Playoffs

Originally posted on Seattle Mariners on SI
By Ryan Boman | Last updated Oct 1, 2025 1:05 PM ET

As the Seattle Mariners prepare for the postseason, they will scrimmage today and tomorrow, and then lock in for this Saturday's Game 1 of the American League Division Series. They have set their roster for the AL Playoffs, and it includes one intriguing arm out of the bullpen.

Left-handed reliever Caleb Ferguson has pitched at the Major League level for the Pittsburgh Pirates in 2025. He was traded to the Mariners in exchange for pitching prospect Jeter Martinez in late July, and he may end up being an invaluable 'extra piece' in the 'pen now that the season has reached crunch time. Not only does he give the M's another lefty to pair with steady Gabe Speiers, but he's potentially a late-inning weapon.

In somewhat limited duty this year, Ferguson has been extra effective against left-handed batters. The 29-year-old veteran has held lefties to just a .184 batting average, with a .465 OPS, with no home runs in 115 plate appearances. More importantly for the Mariners right now? He hasn't given up a run or a hit in seven career postseason appearances.

The Mariners' Bullpen is Set for the Postseason

John Jones-Imagn Images

Aside from Ferguson and Speier, the Mariners have a solid set of arms like Eduard Bazardo, and Matt Brash. While the Mariners' much-maligned middle relief has improved, the main goal of the entire unit is to get the ball to one of the best closers in the game to finish things off.

26-year-old Andres Munoz had his biggest season so far with Seattle. The flamethrower went 3-3 during the season with a career-high 38 saves, posting an ERA of 1.73 and 83 strikeouts, and a 1.03 WHIP in 62.1 innings pitched. He blew seven saves on the season, but was lights-out down the stretch. Munoz has been an American League All-Star over the past two years.

As for Ferguson? He will likely be put into some nail-biting situations against either Cleveland or Detroit. Both teams have some dangerous left-handed bats in their lineups, and the reliever will be under a huge spotlight in key situations.

Based on his track record, he will likely be a quiet hero... or an obvious bust, depending on how his postseason outings go. But the numbers don't lie: If put in the proper position, he can become another weapon in Seattle's slew of hurlers.