The Seattle Mariners selected the contract of third baseman Weston Wilson from Triple-A Tacoma on Friday and designated infielder Miles Mastrobuoni for assignment, according to MLB's official transactions feed.
MLB listed both moves with June 19, 2026 effective and resolution dates. Wilson, 31, moved from the Tacoma Rainiers to the Mariners, while Mastrobuoni, 30, was designated for assignment by Seattle.
Wilson Gets The Roster Spot
Wilson gives Seattle another right-handed infield option. MLB's player database lists him as a third baseman who bats and throws right-handed, with a major league debut date of Aug. 9, 2023.
His 2026 MLB line before the Mariners move came with the Baltimore Orioles: 21 games, 46 plate appearances, a .231 average, a .348 on-base percentage, a .333 slugging percentage, one home run and three RBIs. Those numbers are official MLB stat-feed entries, not projections.
Mastrobuoni Hits DFA Wire
Mastrobuoni had appeared in eight games for Seattle this season, according to MLB's 2026 hitting feed, batting .217 with a .269 on-base percentage and one RBI across 27 plate appearances.
The designation opens the roster path for Wilson but does not itself settle Mastrobuoni's next stop. A DFA gives the club a window to trade, waive or outright the player, so Seattle's follow-up transaction will determine whether he stays in the organization.
MLB Trade Rumors also reported the move Friday, citing the contract selection and corresponding DFA. The official transactions data supplies the central facts: Wilson is up from Tacoma, and Mastrobuoni is off the active roster path for now.