Mariners Outright Miles Mastrobuoni

The Mariners announced that infielder/outfielder Miles Mastrobuoni cleared waivers and has been outrighted to Triple-A Tacoma. He had been designated for assignment by Seattle last week. He does not have three years of big league service time nor a previous career outright, so he does not have the right to reject this assignment in favor of free agency.

Mastrobuoni, 30, is in his fifth season as a glove-first utility guy. He began his big league career with the Rays in 2022, was traded to the Cubs prior to the 2023 season, and then to the Mariners prior to the 2025 campaign. His .230/.295/.273 batting line isn’t much to look at but he has stolen 22 bases and lined up defensively at every position on the diamond except for catcher and center field.

For Seattle, Mastrobuoni spent the 2025 season getting shuttled between Triple-A and the big leagues, as needed. He exhausted his final option in the process. That put him on the roster bubble coming into 2026. He suffered a calf strain in March while playing for Italy in the World Baseball Classic. He began the season on the IL and stayed there until June 10th. He then got into eight games and slashed .217/.269/.217 before the Mariners designated him for assignment.

Though Seattle squeezed Mastrobuoni off the roster, they are likely glad to keep him as non-roster depth. They currently have Brendan Donovan and Will Wilson on the injured list, cutting into their position player group a bit. If another injury pops up, Mastrobuoni could get some consideration, though he may be at a disadvantage now that he’s off the roster. Patrick Wisdom, Ryan Bliss, Leo Rivas, Connor Joe and Brennen Davis all have 40-man spots and are currently on optional assignment. Mastrobuoni will qualify for minor league free agency at season’s end if not added back to the roster.