The Seattle Mariners just added another piece to their pitching puzzle — and it could become a sneaky important move as the postseason race heats up.
Seattle has signed right-handed pitcher from the Detroit Tigers, giving the organization another arm to develop and potentially call upon during the final stretch of the season. The move comes after Detroit designated Watson for assignment while creating space on its 40-man roster.
Instead of returning to the Tigers’ system, the 29-year-old now gets a fresh start with a Mariners organization searching for every possible advantage down the stretch. Seattle has assigned Watson to Triple-A Tacoma, but his arrival gives the club another experienced option waiting in the wings.
Mariners Add Versatile Arm With Impressive Track Record
While Watson has yet to make his Major League debut, his numbers in the minors suggest Seattle may have uncovered an intriguing depth piece.
The right-hander spent most of the 2026 season with Triple-A Toledo, where he showed the ability to handle multiple roles as both a starter and reliever. Across three minor league levels this season, Watson posted a 4-3 record with a 2.83 ERA and a 1.09 WHIP over 60.1 innings.
He also displayed strong command, striking out 44 hitters while allowing only 46 hits. His ability to limit traffic on the bases made him one of Detroit’s more reliable minor league arms before the roster crunch forced the Tigers to make a difficult decision.
With Toledo specifically, Watson recorded a 3.24 ERA and a 1.06 WHIP across 50 innings. He surrendered just 39 hits while collecting 36 strikeouts and issuing only 14 walks, showing the kind of efficiency that can attract teams looking for pitching depth.
The Mariners are also gaining a pitcher with plenty of experience. Watson has logged 456.2 career minor league innings across 178 appearances, including 71 starts. During that span, he owns a 3.86 ERA, 387 strikeouts and nine saves.
Originally drafted by the Toronto Blue Jays in the 15th round of the 2018 MLB Draft out of Northern Colorado, Watson finally reached a major league opportunity when Detroit added him to its 40-man roster in July. However, he was optioned to Toledo and never appeared in a game for the Tigers before being designated for assignment.
Now, Seattle is betting that his next opportunity could come in a Mariners uniform.
Seattle’s Playoff Push Makes Pitching Depth More Valuable
The timing of the move is significant.
The Mariners entered the week sitting at 58-66 and looking to climb back into the American League playoff picture. Seattle trails the Houston Astros and Texas Rangers in the AL West, making every roster decision more important as the season moves toward its final weeks.
After dropping three straight games, the Mariners responded with an explosive 10-5 victory over Houston on Aug. 15. Emerson Hancock delivered seven strong innings, while Seattle’s offense erupted for 15 hits. Cole Young powered the attack with a three-run homer and four RBIs, while Brendan Donovan added three hits and three RBIs.
That win highlighted what Seattle can do when everything clicks — but the club knows pitching depth will be critical if it wants to stay alive.
Watson may begin his Mariners tenure in Tacoma, but his versatility gives the organization another potential solution if injuries strike or the bullpen needs reinforcements. A pitcher capable of starting, relieving, and handling different roles could become a valuable weapon during the final push.
For now, the Mariners are taking a low-risk chance on an arm that quietly put together a strong season. If Watson continues producing the way he did in the minors, Seattle’s latest waiver claim could end up being a much bigger move than expected.