Tampa Bay acquires former Mariners pitcher after DFA

The Tampa Bay Rays have added another arm to their bullpen, acquiring right-handed reliever Casey Legumina from the Seattle Mariners, according to Ken Rosenthal of The Athletic. The trade sends minor leaguer Ty Cummings to Seattle in exchange.

Legumina’s path to Tampa Bay was a quick one. The Mariners designated the 28-year-old right-hander for assignment earlier this week following a rough outing in which he surrendered three tiebreaking runs in the eighth inning of a 6-4 loss to the Oakland Athletics, a performance that proved to be the final straw for a pitcher already on thin roster ice.

The timing of the DFA was no coincidence. Legumina entered 2026 out of options, meaning the Mariners could no longer send him to the minors without exposing him to waivers. After burning his final option year during the 2025 season, in which he made 48 appearances and posted a 5.62 ERA in 49.2 innings, he had to stick on the big-league roster or be made available to the rest of the league.

Legumina has pitched for Seattle eight times this season, giving up 4.63 runs per game and 1.54 walks per game over 11.2 innings. His strikeout-to-walk ratio was only 9:3. His ERA got a little better from 2025, but his strikeout rate dropped to just 17%, which is bad for a reliever who needs to be able to swing and miss to stay in the big leagues.

Legumina, who went to Gonzaga, made his MLB debut with the Cincinnati Reds in 2023. Since then, he has moved between teams, going from the Minnesota Twins to the Reds in a trade and then to Seattle in early 2025 for cash. He has a 5.83 ERA over 83.1 innings pitched in 73 career games.

The Rays’ move is typical of how they build their bullpens: they take low risks and aim for high rewards. Tampa Bay has always been good at getting the most out of reclamation-project arms, and Legumina, who is only 28 and has a live fastball, is a perfect example of this. A lot will depend on whether he can miss bats and limit walks in a new place if he wants to stay on the roster long-term.