Mariners Claim Former UW Catcher After Blue Jays Cut Him Loose
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Seattle claimed a 29-year-old catcher named Willie MacIver off waivers after the Toronto Blue Jays DFA’d him on Aug. 11. It’s a completely modest transaction that carries a local angle. MacIver played three seasons at the University of Washington before the Colorado Rockies picked him in the ninth round of the 2018 draft.
MacIver reached the 2021 Futures Game as a Rockies prospect, made his MLB debut with the A’s in 2025, was then claimed by the Rangers last November and landed with Toronto in an April trade. Now he’s back on the West Coast with the Mariners.
That’s a bunch of organizational movements for one catcher. Which also explains the claim. MacIver has enough interesting traits to continue getting opportunities.
Mariners Bring Willie MacIver Back to Familiar Territory
So let’s talk about the obvious stuff. At 29, the prospect label has expired. He owns a .186/.252/.324 slash line across 102 major-league at-bats. That production won’t force its way into the M’s major league uniform, especially with Cal Raleigh behind the plate.
Still, writing him off as a nothing burger waiver claim would ignore the part of his résumé that keeps teams calling.
He consistently punishes Triple-A pitching. MacIver hit .297 with 15 home runs and a .911 OPS for Albuquerque in 2024. He followed that by hitting .362 with a .426 OBP and a .967 OPS across 54 games for Las Vegas in 2025. Both environments skew towards inflated offensive numbers, so we shouldn’t get too carried away. But even with a proper discount applied, that production is nothing to sneeze at when it’s coming from a catcher.
His 2026 numbers have cooled to a .244 average and .722 OPS, but he has still driven in 40 runs. The Mariners obviously aren’t searching for Raleigh’s replacement. They’re protecting themselves against the reality of a brutal position. Mitch Garver was recently released and signed by the Yankees. And Jhonny Pereda who filled in for Raleigh earlier this season is now his backup catcher. MacIver now becomes part of that insurance policy.
He also carries a reputation that fits the position. During Rangers camp, MacIver became known for constantly encouraging pitchers and bringing loud, relentless energy to bullpen sessions. Texas manager Skip Schumaker compared his personality to Austin Hedges, which is meaningful praise in catcher circles. Pitchers reportedly enjoyed throwing to him because he made every bullpen feel productive.
Clubhouse personality gets oversold when the player cannot contribute. At catcher, communication is part of that contribution. The Mariners have built their identity around pitching. If they have the chance to bring in a backstop who connects with them, they shouldn’t hesitate to stash him in Triple-A.
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Tremayne Person is the Publisher for Mariners On SI and the Site Expert at Friars on Base, with additional bylines across FanSided’s MLB division. He founded the Keep It Electric podcast in 2023 and covers baseball with a blend of analysis, context, and a little well-timed side-eye just to keep things honest. Tremayne grew up a Mariners fan in Richmond, Va., and that passion ultimately led him to move to Seattle to cover the team closely and become a regular at home games. Through his writing, he connects with fans who want a deeper, more personal understanding of the game. When he’s not at T-Mobile Park, he’s with his dog, gaming, or finding the next storyline worth digging into.
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