Reliever's success story with Rays suggests Mariners dropped the ball with his talent

Casey Legumina didn't have the greatest tenure with the Mariners. After being acquired from the Reds in exchange for cash in February 2025, he pitched to a 5.62 ERA over 48 appearances out of the bullpen. He spent most of his time pitching in low-leverage situations and even then, struggled to give the team sufficient run prevention.

He stuck around in 2026 and pitched better, posting a 3.10 FIP over his 11.2 innings with the Mariners, but his 4.63 ERA and low strikeout rate weren't giving Seattle the sort of relief pitching they needed. As a result, he was traded to the Rays after being designated for assignment.

At the time, there wasn't a clear spot for him on the team given the sheer talent in the bullpen but with the team facing more injuries, his success with Tampa Bay may be giving Seattle some seller's remorse.

Casey Legumina has been a solid part of the Rays' bullpen after being traded from the Mariners

Legumina has posted solid numbers with his new squad, pitching to a 2.75 ERA with a 3.76 FIP over 19.2 innings. The Rays are notorious for relying heavily on their relief unit for opening and taking on a lion's share of the innings and he has fit that role very well, often getting more than three outs and taking the ball in nearly every inning, from the first to the ninth.

He doesn't quite have the stuff to be a high-leverage arm, but he has made it work by relying on the strengths he does possess. His fastball averages just 93.3 mph and his whiff and strikeout rates are in the bottom quartile of qualified pitchers, but his walk rate of 5.3% is exceptional as is his average exit velocity of 86.8 mph.

In lieu of sheer velocity, his four-seam has some tail to it, boasting 13.5 inches of arm-side run. It profiles similarly to a traditional two-seam fastball, holding plane for longer while still having some lateral movement. His breaking balls do have impressive shape but they haven't been able to fool batters as much as one would hope. However, he has been more effective with them recently.

It's not often that the Mariners come across a pitcher they can't get the most out of, but no organization is perfect. With a logjam of exceptional pitching talent already in their bullpen, they likely viewed Legumina as an interim piece of the puzzle.

Of course, the injuries that have shelved Cooper Criswell, Matt Brash, and Carlos Vargas have now shifted Seattle's priorities to needing more reliever help at the deadline. Does this mean that the organization was foolish to give up on a player who clearly had value left to offer? Not really.

With 61.1 innings of lukewarm data on Legumina, the lack of upside wasn't worth the roster spot. Additionally, it would've been difficult for Seattle to foresee this many blows to their pitching staff and even then, he'd still be a temporary solution while the front office pursued a more competitive option. If anything, the team has too much pitching and it's causing them to resort to unorthodox methods to try and ensure all of them get enough innings.

It's great that Casey Legumina has bounced back with a new organization but his future with the Mariners was always going to be limited. Could he have been a more impactful arm with more time and attention? Possibly, but with finite resources to go around, Seattle has chosen to invest in more promising projects.

Add us as a preferred source on Google

Follow