Mariners Trade Deadline: Who could be dealt if Seattle sells?

Jul 18, 2023, 12:24 PM | Updated: 12:44 pm

Seattle Mariners Teoscar Hernández...

Seattle Mariners' Teoscar Hernández runs the bases after hitting a double in Houston on July 9, 2023. (AP Photo/Kevin M. Cox)

(AP Photo/Kevin M. Cox)

We’re just two weeks away from the Aug. 1 MLB trade deadline. So what are the Seattle Mariners going to do?

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Obviously, a lot of that depends on what the team does in the win column between now and then. Entering Tuesday evening’s game against the Minnesota Twins, the Mariners are 47-46, eight games back in the American League West and 4.5 games out of the third AL Wild Card spot.

The Mariners could buy, and we’ve seen this front office be aggressive in trades before, such as acquiring Luis Castillo last year and inking him to a long-term contract extension. They could also sell off a few pieces while either acting as straight sellers or doing a bit of both.

So if the Mariners do decide to part with some of the players on their MLB roster, there are a few names to keep an eye on between now and Aug. 1.

Potential Mariners trade pieces

Teoscar Hernández, right fielder

What the heck will the Mariners do with Hernández? That’s the big question with the M’s entering deadline season.

The veteran slugger has had an up-and-down season filled with peaks and valleys, and he’s a pending free agent. Hernández is currently slashing .242/.297/.424 with 15 home runs and 50 RBIs.

If Hernández gets hot over these next few weeks, he’d certainly catch a decent return via trade. But if he’s hot, the Mariners are probably winning and making gains in the standings. It could be argued that no player’s status in trade talks is more tied to the Mariners’ performance these next few weeks than Hernández.

The Marlins, Yankees, Guardians and Reds are all playoff hopefuls who, according to Fangraphs, are in the bottom half of MLB in fWAR by right fielders. Could any of them reach out for Hernández’s service?

If Hernández stays – either because the Mariners improve, a potential trade return isn’t great or so on – then in the offseason the M’s could extend a qualifying offer and either return Hernández for 2024, sign him to a long-term extension, or allow him to sign elsewhere, which would net Seattle a compensatory pick in next summer’s MLB Draft. Outside of Shohei Ohtani, this is a rather thin free-agent hitting class, so Hernández likely won’t have a problem finding a team willing to pay him more than the one-year qualifying offer price tag.

But if a trade works out and the M’s can net a prospect or two they like, or ideally young MLB-ready (or close) talent, then it wouldn’t be too shocking to see the front office pull the trigger.

Paul Sewald, reliever

Sewald completely transformed himself upon joining the Seattle Mariners, going from a struggling arm with the New York Mets to one of baseball’s top back-end relievers over the past three years. In 2023, he owns a 3.11 ERA, 2.70 FIP and 1.009 WHIP while striking out more than 13 batters per nine innings. He also has 19 saves, just one off his career high of 20 from last year.

So why would the M’s potentially part ways with him at the deadline? There are a few reasons.

One, his contract. Sewald is entering his final year of arbitration and will be a free agent after next season. Outside of Andrés Muñoz, this regime hasn’t committed to relievers on long-term contracts.

Two, relievers are always valuable at the deadline, especially back-end arms. Contending teams typically need bullpen help, and adding someone like Sewald to the mix to pitch high-leverage innings would certainly be a boost for most teams with October aspirations (including the Mariners, who obviously could hold on to the veteran right-hander for this year and next).

Three, if there’s one thing this M’s regime can do, it’s develop bullpen arms. From trade additions like Muñoz, Matt Brash and Justin Topa, to minor-league signings like Sewald, to waiver pickups like Gabe Speier, the Mariners have had great success turning lesser-known arms into impact relievers over these last three years. That track record could make a trade of Sewald more likely.

And four, we’ve seen this story play out before. Yes, the Mariners were in a different spot in 2021 as a surprise contender and Kendall Graveman was a pending free agent, but the team still shipped him to a division rival (Houston) during a run that saw them fall only two games short of the playoffs. The M’s do have more work to do now than they did in 2021, though.

The Giants, Red Sox, Reds, Rays and Yankees all rank in the bottom half of MLB in fWAR by relievers, per Fangraphs, and could be teams to watch when it comes to trading for bullpen help. I also think the Dodgers and Diamondbacks are two more teams to watch that could use one more high-leverage arm as they make their runs towards October.

We’ve already seen the reliever trade market start up a little bit with Aroldis Chapman going from Kansas City to Texas, and the M’s traded veteran reliever Trevor Gott recently to the Mets.

Starters not named Luis Castillo or George Kirby

Full disclosure: I don’t think this will happen or should happen.

Young, controllable and most importantly good starting pitching is one of the best commodities in baseball. As such, the Mariners are “rich” in the sense that four of their five starters at this moment are young hurlers who have yet to enter arbitration.

Castillo doesn’t fall into that category as he’s a veteran All-Star locked up with a long-term contract. He’s not going anywhere.

Kirby does, however, fall into that category, but he’s an All-Star who is bordering on No. 1 starter status. Unless the return is just over the moon good and too much to pass on, the second-year hurler won’t be moving. And that’s likely the case.

Logan Gilbert and rookies Bryce Miller and Bryan Woo, however, are coming up in some trade rumors. Friend of the station Jon Morosi of MLB Network has reported the Mariners and St. Louis Cardinals have discussed trades regarding the M’s young pitching and Cards’ young bats, and he thinks the two sides match up well in a trade that could benefit both in the long run. Derrick Goold of the St. Louis Post-Dispatch recently reported that Gilbert is a target of the Cardinals, whose general manager, John Mozeliak, told reporters that the team’s deadline focus is on pitching with an eye ahead to the 2024 season.

The M’s do need some long-term impact bats, and Gilbert, Woo or Miller could certainly help in that regard, be it with the Cardinals (Brendan Donovan, Nolan Gorman and Dylan Carlson have all been rumored to be available) or another team.

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Again, I don’t think it’ll happen or should happen. But it’s obviously worth keeping an eye on as the deadline nears.

Tom Murphy, catcher

Murphy is looking a lot more like the 2019 version of Tom Murphy as he owns an OPS in the mid-.800s with a slugging percentage in the .500s, but he’s played just 33 games this year as he’s the team’s No. 2 option to Cal Raleigh behind the dish.

Raleigh, like many in the M’s lineup this year, is underperforming compared to last year when he led MLB catchers in home runs with 27. That potential coupled with many years of club control mean he’s not going anywhere anytime soon.

Murphy, however, is a pending free agent and has had a hot bat this year. Many contenders (Rays, Yankees, Reds, Giants) could stand for upgrades behind the plate heading into October. With the universal DH, Murphy could also help a team’s lineup in general as a catcher/DH, or as a platoon guy to face left-handed pitching, which is where the majority of his at-bats have come this year (though he still owns an OPS over .800 versus righties).


As noted with Sewald, bullpen arms are always worth watching, so maybe a team pulls the trigger for Topa or Speier as they’re in the midst of career seasons.

I don’t think Eugenio Suárez goes anywhere, mainly because he’s still owed $11 million for next year and has a $15 million team option for 2025, per Spotrac.

Ty France has two years of arbitration ahead of him and is also having a lackluster season at the dish (sub-.700 OPS), so the M’s likely wouldn’t get much in return for him now and would aim for him to either get right at the plate or have a bounceback season in 2024.

More on the Seattle Mariners

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Morosi: The great sales pitch Seattle Mariners have for Shohei Ohtani
Why Angels reporter thinks Mariners are on Ohtani’s shortlist
Dipoto: Why Mariners went with 3 HS bats to begin 2023 MLB Draft
Morosi: Where do Seattle Mariners stand with trade deadline nearing?

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