Inside The Mariners

Seattle Mariners Send Strong-Armed Reliever Gregory Santos to Triple-A

The Mariners opted to send Santos to the Tacoma Rainiers and brought up Will Klein in a corresponding move.
Seattle Mariners pitcher Gregory Santos (right) talks with catcher Cal Raleigh during a game against the Texas Rangers on April 12 at T-Mobile Park.
Seattle Mariners pitcher Gregory Santos (right) talks with catcher Cal Raleigh during a game against the Texas Rangers on April 12 at T-Mobile Park. | Joe Nicholson-Imagn Images

In this story:


The Seattle Mariners bullpen has been one of the most volatile units on the team in 2025 in terms of transactions. Right-handed relievers Troy Taylor and Matt Brash began the year on the 15-day injured lists with respective injuries. Taylor was just activated off the injured list on Monday.

The Mariners have one of the highest-ranking bullpens in the league in terms of innings pitched. And that's forced them to go to make several roster moves and transactions to cover the relievers' high usage.

Seattle's latest move related to the bullpen will temporarily demote one of the strongest arms on the team to the Triple-A Tacoma Rainiers.

Before Game 2 of a three-game series against the Cincinnati Reds on Wednesday, the Mariners optioned right-handed pitcher Gregory Santos to Tacoma. They recalled right-handed reliever Will Klein in a corresponding move.

Santos has had a chaotic stint with Seattle. The organization acquired him in a trade with the Chicago White Sox on Feb. 3, 2024. He was out for most of last season due to two separate stints on the injured list: one for a right lat strain and the other for right biceps inflammation. Santos pitched in eight games last season and had a 4.91 ERA with six strikeouts in 7.1 innings pitched.

This season, Santos has had eight outings already. He has a 5.14 ERA in seven innings pitched and is yet to record a strikeout. He's allowed six runs (four earned) in his last four appearances.

Santos has one of the strongest arms on the pitching staff with a fastball capable of hitting triple-digits. But he's struggled with command to start the year.

The Mariners will hope Santos can recover his form with the Rainiers that he had with the White Sox. In 2023, Santos had a 3.39 ERA in 60 appearances with 66 strikeouts in 66.1 innings pitched.

Related Stories on Seattle Mariners

JESSE HAHN SIGNS MINOR LEAGUE CONTRACT WITH SEATTLE MARINERS: The right-handed reliever made two appearances for the team before being designated for assignment. CLICK HERE

SEATTLE MARINERS BLOW EARLY LEAD IN 8-4 LOSS TO CINCINNATI REDS: The Mariners pitching staff had an uncharacteristically bad showing and a two-home run game from Dylan Moore went to waste Tuesday against the Reds. CLICK HERE

MARINERS STARTING PITCHER EMERSON HANCOCK LIKELY TO GET CALLED UP ON ROAD TRIP: Indications are the Mariners will call up the former Georgia pitcher for his second start of the season against the Toronto Blue Jays. CLICK HERE

Follow Seattle Mariners on SI on social media

Continue to follow our Inside the Mariners coverage on social media by liking us on Facebook and by following Teren Kowatsch and Brady Farkas on "X" @Teren_Kowatsch and @RefuseToLosePod. You can subscribe to the "Refuse to Lose" podcast by clicking HERE.


Published | Modified