Former Mets’ reliever claimed off waivers by AL West playoff team

A former New York Mets reliever was claimed off waivers by the Seattle Mariners on Wednesday.

Jul 25, 2025; San Francisco, California, USA; New York Mets pitcher Jose Castillo (54) throws a pitch during the ninth inning against the San Francisco Giants at Oracle Park. Mandatory Credit: Sergio Estrada-Imagn Images | Sergio Estrada-Imagn Images

After being designated for assignment on August 30th by the New York Mets, reliever José Castillo was claimed off waivers by the Seattle Mariners on Wednesday.

Castillo, 29, was acquired from the Arizona Diamondbacks on May 15th for cash and appeared in 16 games with the Mets. He struggled in Arizona, posting an 11.37 ERA and 2.05 WHIP through 6.1 innings in the desert.

José Castillo has been claimed off waivers by the Mariners https://t.co/QvpcXoxXOt pic.twitter.com/P0cwlXo7NO

— SNY (@SNYtv) September 3, 2025

The southpaw fared a bit better in his short stint with the Mets, as he produced a 1-1 record with a 2.35 ERA and 1.761 WHIP across 15.1 innings of work. His last appearance for the Mets was on August 29th against the Miami Marlins before he was DFA’d the following day.

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Castillo seems to be a casualty of the roster shuffle the Mets have seen since the trade deadline. New York added multiple bullpen arms in lefty Gregory Soto from the Baltimore Orioles, Tyler Rogers from the San Francisco Giants, and Ryan Helsey from the St. Louis Cardinals.

Helsey was viewed as the top candidate to set up for closer Edwin Diaz in the eighth innings, but has struggled since arriving in Queens. After Wednesday’s loss to the Detroit Tigers, Helsey has now ceded 14 earned runs in his 11 innings of work with the Mets; Rogers and Soto have fared better, but the inconsistency in the bullpen has been a major driver of the Mets’ second-half struggles.

Ryan Helsley has allowed 14 ER in 11 IP as a Met (11.45 ERA)

He allowed 12 ER in 36 IP as a Cardinal (3.00 ERA) pic.twitter.com/DUFcPuFhR0

— SNY Mets (@SNY_Mets) September 3, 2025

In Seattle, Castillo finds himself in a very similar situation to the Mets. The Mariners are holding the final AL Wild Card spot and are just 1.5 games ahead of the Texas Rangers, and are 4.5 games back of both the Boston Red Sox and the New York Yankees. Seattle is also three games back of the Houston Astros for the AL West division lead.

We have claimed LHP José Castillo off waivers from the Mets and he has been added to the 40-man roster. #TridentsUp

🔗 https://t.co/lXQuxmnmP0 pic.twitter.com/JfLtdGvFUv

— Seattle Mariners (@Mariners) September 3, 2025

To make room for Castillo on the 40-man roster, the Mariners designated lefty Joe Jacques for assignment. Castillo is out of options for the season, so Seattle will need to make a roster move once he officially joins the team.

With the Mariners, Castillo will join a bullpen that already has lefties Gabe Speier, Caleb Ferguson, and Tayler Saucedo. Before joining the Diamondbacks this year, Castillo was in the San Diego Padres organization for five years. He is currently on a one-year, $760,000 contract and will be a free agent after 2026, which is his third year of arbitration eligibility.