The Mariners have selected the contract of infielder/outfielder Weston Wilson. Fellow infielder/outfielder Miles Mastrobuoni has been designated in a corresponding move. Prior to the official announcement, Adam Jude of The Seattle Times noted Wilson was in the clubhouse. Daniel Kramer of MLB.com indicated Mastrobuoni would likely be designated for assignment to make room.
Kramer suggests the swap is related to the fact that the Mariners are slated to face a bunch of lefties. The Red Sox are scheduled to start southpaws Ranger Suárez, Connelly Early and Payton Tolle this weekend. Seattle’s regular lineup is mostly filled with lefty bats, including J.P. Crawford, Josh Naylor, Dominic Canzone, Luke Raley, Cole Young and Colt Emerson. Righties Connor Joe and Rob Refsnyder are on the bench but Joe has a .189/.302/.324 line this year while Refsnyder is at .143/.214/.242.
Mastrobuoni and Wilson are both multi-positional types but the former hits from the left side and the latter the right. The 31-year-old Wilson has a .240/.331/.413 line in 291 plate appearances from 2023 to 2026, a line that translates to a 108 wRC+. That breaks down as a .248/.351/.456 line and 124 wRC+ against southpaws compared to a .229/.302/.352 line and 83 wRC+ in the other half of the split.
Defensively, Wilson has big league experience at every position on the diamond except for shortstop and catcher. Though he’s never played short in the big leagues, he has spent a decent amount of time there in the minors. He should give manager Dan Wilson a good amount of flexibility in trying to get through this gauntlet of lefties. He was with the Orioles earlier this year but got bumped from that club’s roster, allowing Seattle to sign him to a minor league deal this week.
After this Boston series, the Mariners play the Pirates, who have an all-righty rotation. Wilson is out of options, so perhaps he is in line for a short stay on the roster if the M’s want to shuffle things up again in a few days. Then again, Joe is still optionable and has been struggling, so sending him down could be another possibility.
Optimizing the roster will cost Mastrobuoni his spot. The 30-year-old is in his fifth big league season, having previously spent time with the Rays and Cubs. He was acquired by the Mariners in a cash deal in February of 2025 after being designated for assignment by Chicago. He has generally been a serviceable but light-hitting bench guy. From 2022 to 2024, he hit .231/.296/.276 in 447 plate appearances but played all four infield positions and the outfield corners.
He has barely gotten going this year. He started the season on the 10-day injured list due to a right calf strain. He was later transferred to the 60-day IL. He was activated a little over a week ago. He has a .217/.269/.217 line in 27 plate appearances since then.
Mastrobuoni exhausted his final option year in 2025, leaving him now out of options. He might have started the season on the roster bubble but the IL placement allowed him to technically linger in the mix for almost half the season, but he has now been bumped off.
DFA limbo can last as long as a week. The waiver process takes 48 hours, so the M’s could take as long as five days to explore trade interest. If he were to clear waivers, he would stay in the system as non-roster depth. He doesn’t have a previous career outright and is shy of three years of service, so he wouldn’t have the right to reject an outright assignment in favor of free agency.
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