Seattle Mariners reliever Trent Thornton throws during a game against the Miami Marlins on April 27 at T-Mobile Park. Stephen Brashear-Imagn Images

Seattle Mariners Activate Reliever Trent Thornton Off Injured List

Originally posted on Seattle Mariners on SI
By Teren Kowatsch | Last updated Jun 7, 2025 4:00 PM ET

The Seattle Mariners received a needed boost to the bullpen on Saturday with the return of reliever Trent Thornton.

Thornton was activated off the 15-day injured list before a game against the Los Angeles Angels. He was placed on the IL on May 9 (retroactive to May 6) after undergoing surgery for appendicitis. Casey Lawrence was designated for assignment in a corresponding move to make room on the 40-man roster.

Roster Moves:

Trent Thornton, RHP, reinstated from 15-day Injured List (appendicitis).
Casey Lawrence, RHP, designated for assignment.

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— Mariners PR (@MarinersPR) June 7, 2025

Thornton had a 5.87 ERA with 11 strikeouts in 15.1 innings pitched across 16 appearances before landing on the shelf. He had a pair of rehab appearances for the Triple-A Tacoma Rainiers, where he posted a 3.38 ERA and fanned three batters in 2.2 innings.

Amped Cam™: Trent Thornton, after pitching a scoreless 7th inning to preserve the Mariners' 2-1 lead. pic.twitter.com/Cf5XZhnp6U
— Daniel Kramer (@DKramer_) April 8, 2025

Thornton first started to feel discomfort during Seattle's road series against the Athletics on May 5-7. Thornton said he originally thought it was stomach cramps. The pain persisted, and it wasn't until the team returned to Seattle on an off-day May 8 that trainers advised Thornton it could be his appendix and advised him to go to the emergency room.

Thornton took the trainers' advice, and doctors confirmed it was his appendix and operated on him.

Thornton is in the middle of his third season with the Mariners. He had a career-high 71 appearances for Seattle in 2024 and had a 3.61 ERA with 77 strikeouts in 72.1 innings pitched.

The Mariners bullpen has been racked with injuries and has been used a high amount this season. Another reliever, Collin Snider, landed on the injured list Wednesday due to a right flexor strain.

Thornton will give Seattle another option in high leverage situations.

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

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