Mariners Lose Free-Agent Pitcher To Cubs After Rough Ending In Seattle

A genuine big-league arm to Chicago?

Jun 29, 2025; Arlington, Texas, USA; Seattle Mariners pitcher Trent Thornton (46) reacts after the final out against the Texas Rangers during the twelfth inning at Globe Life Field. Mandatory Credit: Tim Heitman-Imagn Images | Tim Heitman-Imagn Images

The Seattle Mariners turned over their bullpen at the end of last season, non-tendering three pitchers who had fairly large past roles in November.

Trent Thornton, the 32-year-old righty who was set to be arbitration-eligible for the final time, found himself non-tendered after he tore his Achilles tendon in August during his first outing after the trade deadline. Though he wasn't having his strongest season by any means, he was a considerable loss for Seattle at the time.

Though Seattle non-tendered Thornton over what was likely to be a $3-5 million price tag due to his seniority, it's possible the club wanted him back if they could get him for cheap. However, he ultimately chose a new team, and one with a lot more openings in its bullpen to boot.

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Trent Thornton heads to Cubs, per Tread Athletics

Apr 16, 2025; Cincinnati, Ohio, USA; Seattle Mariners relief pitcher Trent Thornton (46) pitches against the Cincinnati Reds in the sixth inning at Great American Ball Park. Mandatory Credit: Katie Stratman-Imagn Images | Katie Stratman-Imagn Images

According to a Monday post from Tread Athletics, Thornton's offseason training facility, the righty signed a minor-league deal with the Chicago Cubs.

The post also included video of Thornton throwing a bullpen at Tread's pro day, and although there will still be plenty of procedural hurdles to clear, the veteran sure didn't look like a pitcher unable to push off a torn Achilles.

Check out the bullpen that helped him get a deal! pic.twitter.com/J64oCMPSkp

— Tread Athletics (@TreadHQ) January 19, 2026

In his 42 1/3 innings last season, Thornton posted a 4.68 ERA and struck out only 32 batters. The season before, however, he posted a 3.61 ERA. And in 2023, when he was traded from the Toronto Blue Jays to the Mariners, he had a career year with a 2.01 ERA (albeit in a smaller sample than most, with only 31 1/3 innings).

The Cubs have had a banner offseason, with the additions of third baseman Alex Bregman and starting pitcher Edward Cabrera, but there will also be a large group of veterans, many of whom are on minor-league deals like Thornton, fighting for roster spots in spring training.

It will be intriguing to see how things develop for Thornton, but the Mariners are moving on with what they believe to be their standard, excellent bullpen.

More MLB: Mariners Sign 31-Year-Old Veteran With Cubs, Phillies Ties