Mariners Rumors: In-division blockbuster trade could become deadline possibility

We're now just 10 days away from one of the most important trade deadlines of Jerry Dipoto's tenure with the Seattle Mariners. This is a team which needs to (at least) qualify for the playoffs and there are several needs, including adding quality depth to the bullpen.

While the bullpen includes the likes of Andrés Muñoz, Matt Brash and Gabe Speier, it ranks just 13th in the majors in ERA, as well as 18th in WHIP, batting average and strikeouts. As for who the Mariners should consider, MLB insider Ken Rosenthal has mentioned an intriguing target from one of their divisional rivals.

In an article for The Athletic (subscription required), Rosenthal writes that the Athletics will consider changing their official stance of not trading Mason Miller, so long as anyone proposes a good enough offer to consider. However, there are only a few teams which might entice the A's, including the usual suspects of the New York Yankees, Los Angeles Dodgers and Philadelphia Phillies.

What will it take for the Mariners to acquire Mason Miller?

Rosenthal adds the Mariners and San Diego Padres as possibilities, just because he will never rule out Dipoto and A.J. Preller when it comes to top talent. The key to all of this though, is that the asking price is expected to be extortionate for a pitcher who is earning $765K in 2025 and is under club control for four more seasons through salary arbitration.

This isn't the first time we've written about Miller being linked to the Mariners, who we know have the type of quality haul the Athletics would be looking for. Of course this leads to the question of if the 2024 All-Star is worthy of such a hefty return package?

On a peripheral surface level you can make the case that Miller has regressed after his tremendous 2024 campaign. However, go deeper and you can see the quality and results are still there, including a 2.87 FIP, 1.065 WHIP and ridiculous 40.1 strikeout rate which is in the top one percent of the league.

Mason Miller ranks highly in a lot of areas

On the subject of top of the league, Miller's Baseball Savant page is littered with high rankings, including being in the 100th percentile for fastball velocity, 99th percentile for Whiff%, 98th percentile for xBA and 97th percentile for Chase%. The main perceived negative is his 4.04 ERA, but even this can be countered by his expected 2.84 ERA.

Further on that last point, the 26-year-old has seen a strong improvement in his outright ERA as the season has progressed. Through the first 18 appearance of 2025 he had a concerning 6.11 ERA, but since then he's produced an impressive 2.00 ERA in his 17 most recent outings.

Again, this is really more about how much of a trade package it would take to acquire Miller, and if he is really worth it? At the end of the day as much as the Mariners do have the pieces and even though he would undoubtedly boost the bullpen, we'd contend there are other areas of the team which are a higher priority to be strengthened.