Seattle Mariners closer Andres Munoz throws during a game against the Houston Astros on May 23 at Minute Maid Park. Erik Williams-Imagn Images

Seattle Mariners Closer Andres Munoz Makes Franchise History With Latest Outing

Originally posted on Seattle Mariners on SI
By Teren Kowatsch | Last updated May 24, 2025 4:00 PM ET

Seattle Mariners closer Andres Munoz has a legitimate argument to being the best reliever in baseball this season.

Munoz made the All-Star game for the first time in 2024. He posted a 2.12 ERA with 77 strikeouts in 59.1 innings pitched and had 22 saves in 27 opportunities that year. Munoz has followed up his All-Star campaign with an even better season, and has made franchise history in the process.

Munoz is yet to allow an earned run entering Saturday. He has a 0.00 ERA, has fanned 28 batters in 22.2 innings pitched in 23 outings and has a major league-leading 17 saves in 19 opportunities. He has a 0.706 WHIP and is holding opposing batters to a .108 average (8-for-74).

According to pregame notes shared by Mariners PR, Munoz's 22.2 innings without allowing an earned run is the longest stretch to start a season for a reliever in franchise history.

Andrés Muñoz, Filthy 89mph Slider. pic.twitter.com/G7Y8akAxfU
— Rob Friedman (@PitchingNinja) May 4, 2025

According to the same set of pregame notes, Munoz also leads all major league relievers in Baseball Reference WAR (bWAR) with 2.1. That's already 0.1 bWAR more than his All-Star season in 2024.

Munoz has been the anchor for a Seattle bullpen that was racked with injuries and inconsistencies to start the year while also having a high usage rate. Entering Saturday, the Mariners relievers were sixth in the majors and second in the American League with 192.2 innings pitched.

Munoz is the defending American League Reliever of The Month. At his current rate, he'll likely add more hardware to his trophy case by the end of the season and is a leading candidate to win AL Reliever of The Year.

This article first appeared on Seattle Mariners on SI and was syndicated with permission.

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