The Seattle Mariners are poised to make a major move ahead of the trade deadline. After reaching the American League Championship Series in 2025, Seattle has not been able to recreate similar magic this season. As of now, the Mariners are one game under .500 with 65 games left on the schedule.
Despite this, the A.L. West is currently wide open, and Seattle is holding on to the final wild card spot. Because the Mariners are barely holding on to a place in the playoffs, the team’s president of baseball operations, Jerry Dipoto, is expected to target at least one significant trade. Seattle has been linked with a right-handed slugger for weeks now. While this is still an option, Dipoto could also use bullpen help.
Bleacher Report’s Zachary Rymer is now claiming that the Mariners could put together the best trade package for superstar closer Mason Miller. The San Diego Padres only just landed the relief pitcher a year ago in a blockbuster deal with the Athletics. Nevertheless, Padres general manager A.J. Preller is known to make bold moves and could look to offload Miller while his value is sky-high.
According to Rymer, the Seattle Mariners may part ways with star pitcher George Kirby and prospect Michael Arroyo to land Miller. Kirby has been a reliable starter for Seattle since landing in the rotation in 2022. The righty has a 3.76 ERA and 1.31 WHIP in 18 starts so far this season. Arroyo, on the other hand, is the Mariners’ fourth-ranked prospect at the moment.
Landing Mason Miller Would be Worth the Risk for the Seattle Mariners
GettyPadres closer Mason Miller is one of the most dominant pitchers in baseball.
Recent reports claim that the Seattle Mariners are open to trading one of their starting pitchers to bring in a bat or reliever. The club currently has six quality pitchers in their rotation and can afford to lose one. Dipoto would almost certainly prefer the outcast to be Luis Castillo. The veteran’s value, however, is not high enough to help land Miller.
Seattle’s top pitching prospect, Kade Anderson, is also dominating AA hitters this season and could be promoted in the near future. Potentially letting go of Kirby could still be risky. Yet Rymer points out that the 28-year-old starter could be difficult to sign a long-term contract. Statistics also show potential problems with Kirby. He currently has the lowest strikeout per nine innings rate (8.0) and the highest hits per nine innings rate (9.9) in the Seattle Mariners rotation.
Possibly trading away Arroyo would also sting. The versatile infielder/outfielder slashed an impressive .287/.364/.456 with AA Arkansas in 2026. Since being promoted to AAA, Arroyo has been even better. While the sample size is small, the slugger has posted a 1.13 OPS in six games with Tacoma. He can play four different positions on the field as well.
Seattle’s Closer has Been Weak Link in Bullpen
Landing Miller would be a massive move by Dipoto and the Seattle Mariners. While they would have to give up a significant package, Miller is arguably the top relief pitcher in baseball. At the moment, Seattle has one of the best bullpens in baseball. However, the typically reliable Andres Munoz has struggled to finish off games in 2026.
Adding Miller to the group in Seattle would likely cement the team’s position atop the bullpen rankings. The Padres closer has posted a 0.91 ERA and 0.78 WHIP to go along with a league-leading 25 saves this season. Miller is also not set to become a free agent until after the 2029 campaign.
Seattle Mariners would receive: Mason Miller
San Diego Padres would receive: George Kirby and Michael Arroyo
Mariners Trade Proposal Would Land Star Pitcher from Padres