MLB Trade Rumors confirmed the move, and it's the kind of stretch-run transaction that barely registers outside of the front office but says plenty about how the Mariners are managing their pitching depth heading into September.
Watson never actually threw a pitch for Detroit. The Tigers added him to their 40-man roster on July 19, but he stayed stashed at Triple-A Toledo the whole time, and when Riley Greene landed on the injured list with a hamstring strain, Watson got squeezed off the roster to clear a 40-man spot for outfielder Corey Julks. He cleared waivers before Seattle scooped him up.
The résumé is legit for a guy without a big-league inning to his name. Watson has bounced around as a swingman at Toledo this season, running a 2.88 ERA and 1.14 WHIP across 56.1 innings, numbers that had him on the radar as a real September call-up candidate before the DFA. Toronto originally drafted him in the 15th round back in 2018 out of Northern Colorado, and he landed with the Tigers organization in a 2024 move before Detroit ever gave him the 40-man look.
For Seattle, this is pure organizational insurance. The Mariners have leaned on waiver claims and depth pickups all year to keep the pitching staff stocked as they push for a playoff spot, and stashing a 29-year-old arm with a sub-3.00 ERA at Triple-A costs nothing and could pay off if the bullpen needs a fresh face in September.
Don't expect Watson to be a household name anytime soon. But if he ends up making his MLB debut in a Mariners uniform after Detroit gave up on him mid-season, it's the kind of small transaction that becomes a fun footnote if it works out.