Seattle Mariners 2024 Season Preview

Despite all the obstacles standing in Seattle's way, this could be the best Mariners roster Jerry Dipoto has ever put together.

Julio Rodriguez of the Seattle Mariners celebrates his solo home run with the trident prop during the fourth inning against the Texas Rangers.
SEATTLE, WASHINGTON - SEPTEMBER 28: Julio Rodriguez #44 of the Seattle Mariners celebrates his solo home run with the trident prop during the fourth inning against the Texas Rangers at T-Mobile Park on September 28, 2023 in Seattle, Washington. (Photo by Steph Chambers/Getty Images)

The Seattle Mariners began the 2023 season with no shortage of expectations, having just broken their 21-year postseason drought and having gone toe-to-toe with the Astros in every game of the 2022 ALDS.

The past year, however, ended in massive disappointment. Despite winning 88-plus games for the third consecutive season (marking just the second stretch in franchise history in which they have done so), the Mariners were eliminated from playoff contention in Game 161.

Their division foes, the Astros and Rangers, punched their postseason tickets, with Texas ultimately hoisting its first World Series trophy.

The front office knew the roster needed overhaul. And despite not doing much via the free agent route, overhaul they did. Jerry Dipoto and company continued to be one of the busiest and most active teams this winter, as they often are, to find the necessary reinforcements (within ownership’s budget) to get the team back into the postseason.

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After the Mariners put up the second highest strikeout rate in the league in 2023, they parted ways with their four most punchout-prone bats in Eugenio Suarez, Jarred Kelenic, Teoscar Hernández and Mike Ford (all four corralled a K% of above 30%). They replaced them with the likes of Jorge Polanco, Mitch Garver, Mitch Haniger, Luke Raley and Luis Urías – five guys who can help give the lineup more balance with significantly fewer strikeouts.

If that wasn’t enough, Seattle capped the offseason by acquiring one of the most electric relievers in the sport. The trade for Gregory Santos gives the current iteration of the Mariners bullpen a chance to be the best group the organization has ever assembled.

2024 Seattle Mariners Projected Lineups

Projected Lineup vs RHPProjected Lineup vs LHP
1. SS J.P. Crawford1. SS J.P. Crawford
2. CF Julio Rodríguez2. CF Julio Rodríguez
3. 2B Jorge Polanco3. 2B Jorge Polanco
4. DH Mitch Garver4. DH Mitch Garver
5. C Cal Raleigh5. C Cal Raleigh
6. LF Luke Raley6. LF Luke Raley
7. 1B Ty France7. 1B Ty France
8. RF Dominic Canzone8. RF Mitch Haniger
9. 3B Josh Rojas9. 3B Luis Urias

All of a sudden, this lineup really has depth to it. Since Robinson Canó and Nelson Cruz left after 2018, the Mariners have not come close to replacing their production at either DH or second base. This is looking like the year that finally changes.

Designated Hitter

The key for Mitch Garver will be health. Last year he put up a gaudy 138 wRC+ with 19 home runs, appearing in the most games he has played since 2019. The problem? That number of games was only 87. In 2019, it was 93.

Garver has played over 100 games just once in his career (103 in 2018) and has long had issues staying on the field. That being said, most of his injuries have been a result of his time behind the plate. To preserve his health, the Mariners will have Garver serve as their full-time DH, which should keep him much less banged up.


Jorge Polanco has played just 184 games over the last two years. That said, he hasn’t had nearly as many injury issues as Garver, and he played a full season as recently as 2021.

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The 30-year-old has a 117 wRC+ over the past five years and has posted a wRC+ higher than 118 in each of the last four full seasons. Of all of the second basemen made available this winter, via free agency or trade, there is a good case that Seattle acquired the best one out there.

Over the last two years, Cal Raleigh has been one of the best catchers in the game. He led all backstops in home runs a season ago and placed within the top five in fWAR. He also has an incredible arm behind the plate and is a borderline elite pitch framer.

Ty France is entering 2024 with a vengeance. He is coming off a down year in which he barely eclipsed the .700 mark with his OPS, while posting full-season career lows in batting average, home runs, hits, and wRC+.

In response, France made his way to Driveline this winter to re-tool his swing. As a result, he came into spring training having added an eye-popping 3.5 MPH to his swing speed. Between the reports from Driveline and France’s small sample of at-bats this spring, he appears ready to bounce back in 2024.

J.P. Crawford had a career year in 2023. While his defense has taken some steps backward over the last couple of seasons, it was much outweighed by his bat. He set new career highs in home runs (19), OPS (.818) and wRC+ (134).

Now firmly penciled into the leadoff spot for Seattle, Crawford does everything that a table-setter is asked to do – and more. He reaches base (.380 OBP and a near 15% BB% in 2023), collects hits (142 in 2023), and does not strike out (career K% of 18%).

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It almost goes without saying, but this team goes as Julio Rodríguez goes. It is no coincidence that the Mariners combined 38-15 record in July and August last year occurred at the same time as the best two months of the young superstar’s season.

Rodríguez posted nearly a six-fWAR season in just his second trip around the sun in the majors, yet he walked away from 2023 both hungry and unsatisfied. A lot of this is because he had a 103 wRC+ in the first half. If Rodríguez puts his head down and works like never before after finishing in the top five in the AL MVP race, there are no limits to what his 2024 can be.

Dominic Canzone has a real opportunity to break out in 2024. After slashing .354/.431/.634/1.065 in the minors before his call-up, he showed flashes of his potential in 2023; he could be a 20-plus home run bat with a low strikeout rate. He also made some swing adjustments over the offseason and has an OPS over 1.000 this spring. He is very much the popular pick in Mariners circles to have a breakout year.

Luke Raley was one of the best hitters in baseball through the first half of 2023 with a .925 OPS and a 155 wRC+. He tailed off in the second half (.677 OPS and a 93 wRC+) and battled through some injuries in that time, but ultimately finished with a 130 wRC+ and a 2.6-fWAR season. Putting together a complete season is still on his bucket list, but at his best, he can be a true middle-of-the-order bat.

Projected Bench

C Seby Zavala, INF Luis Urias, OF Mitch Haniger, INF/OF Dylan Moore

Two of the four, Haniger and Urías, are not true bench players. They are simply the other halves of a platoon in right field and at third base, respectively.

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The Mariners firmly believe that Urías is a prime bounce-back candidate. He is coming off a rough year in 2023, but he had back-to-back two-fWAR seasons with the Brewers in 2021 and ’22. He barely played 50 games last year, but he has always had a great awareness of the strike zone and does not strike out at a high clip.

Haniger played just 61 games with the Giants last year, but the Mariners know what a healthy Haniger can look like. And that version of him was on center stage not too long ago (back in 2021, to be exact). Platooning Haniger will keep him off his feet more often, and help Scott Servais play to his strengths (career .840 OPS vs left-handed pitching). Plus, Haniger has had a phenomenal spring.

Moore is a jack of all trades. When at his best, he can be an ideal utility player; he hits lefties well, walks, has some power, steals bases and can play every position. He had a down year in 2023, part of which was due to missing all of spring training and the first two months of the season with an injury.

Zavala will fill the role of the secondary catcher, taking the field when Raleigh needs a day off.

2024 Seattle Mariners Projected Rotation

Projected RotationRotation Depth
1. RHP Luis CastilloRHP Emerson Hancock
2. RHP George KirbyRHP Levi Stoudt
3. RHP Logan GilbertRHP Casey Lawrence (not on 40-Man)
4. RHP Bryce MillerRHP Jhonathan Diaz (not on 40-Man)
5. RHP Bryan Woo

Luis Castillo has been everything the Mariners could have asked for and more since the day they traded for him. He is expected to once again be a Cy Young contender after finishing fifth in 2023.

Castillo has thrown one of the most unhittable four-seam fastballs in baseball since arriving in Seattle (+27 Run Value, per Baseball Savant). He made an AL-leading 33 starts last year, going at least six innings in 23 of them and at least seven innings in 10.

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He did start to get hit a little bit harder last year but also walked fewer hitters. Nonetheless, Castillo is a No. 1 starter in every sense of the term and should continue to be one in 2024.

George Kirby, meanwhile, is a 1A to Castillo. The king of strike-throwing once again led MLB in BB% and BB/9, all while posting a 3.35 ERA, receiving his first All-Star Game nod, and continuing to touch 100 MPH.

Kirby doesn’t strike a ton of hitters out, but he may prefer it that way. Doing so keeps his pitch count down and allows him to work deep into games; he went seven innings or more 11 different times in 2023. Kirby placed eighth in AL Cy Young voting last year and has high Cy Young odds entering this season. In other words? He really is not far off from winning.

Logan Gilbert threw nearly 200 innings last year. He already had five pitches, including a wipeout slider, and has now added a sixth offering after learning a cutter this winter. Gilbert could stand to cut down on the hard-hit baseballs he allows, but his command has reached elite territory (top ten in BB/9 in 2023).

After posting back-to-back three-fWAR seasons, Gilbert has a chance to take a big jump forward in 2024, going from very good to great. Perhaps he could even make his first All-Star team.

The two second-year starters, Bryce Miller and Bryan Woo, were asked to do much more as rookies than what was originally expected. But each rose to the occasion.

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Miller and Woo had their typical rookie struggles, one of which was retiring lefties; opposite-handed hitters posted an OPS above .900 against each of them. Yet, Miller flashed life on a fastball that hitters couldn’t touch early on and has now added what looks to be a wicked splitter to his arsenal this offseason.

Woo, meanwhile, is incredibly deceptive with a very low release point combined with a lot of fastball rise. He doesn’t get hit hard and was a product of some bad luck as a rookie (3.48 xERA). With two high-octane heaters, he has the stuff to one day be a top-of-the-rotation starter.

2024 Seattle Mariners Projected Bullpen

Projected Bullpen
RHP Andrés Muñoz
RHP Matt Brash*
RHP Gregory Santos*
RHP Ryne Stanek
LHP Gabe Speier
LHP Tayler Saucedo
RHP Trent Thornton
RHP Austin Voth
RHP Cody Bolton
RHP Collin Snider
*Injured list

The Mariners’ bullpen will be down two of its top weapons to begin the year. Matt Brash will start on the Injured List due to elbow inflammation and Gregory Santos will be placed on the IL with a minor lat strain.

All the more reason, then, that the addition of Ryne Stanek will be extremely helpful. He will pitch in a lot of high-leverage situations early in the year with the aforementioned Brash and Santos on the shelf. Stanek had a down year in 2023 but was as dominant as any reliever in baseball in ‘21 and ‘22. He has elite stuff on both his fastball and slider (per Stuff+). 

Above all of that, the Mariners still have Andrés Muñoz. The flamethrower had foot surgery last offseason, causing him to miss most of spring training in 2023. He would then hit the IL early last April for about two months. The extended time off caused his slider to lose its swing-and-miss stuff last year, though he did pick up an effective sinker.

This year, Muñoz is coming off a proper, healthy offseason and looks as fearsome as ever with Opening Day around the corner.

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Finally, don’t sleep on the lefties Gabe Speier and Tayler Saucedo, both of whom worked wonders last year. Speier does everything one could ask of a reliever between a high strikeout rate, a high groundball rate, and a low walk rate – plus he throws more first-pitch strikes than anyone in baseball. Saucedo also gets a healthy dose of groundballs. He thrives on his sinker, seldom allowing barrels.

Final Thoughts

Despite all the obstacles, this looks to be the best roster the Mariners have put together since Dipoto took over in 2016. 

It is a full step up from last year’s team. The Mariners have one of the top rotations and bullpens in the game, paired with an offense that will strike out less and produce more, and one that is free of black holes at any spot in the order. It is not the best offense in baseball by any means, but it is a group that is more than capable of making a run. The lineup certainly will not hold the team back.

The overarching theme for the team all year will be maintaining health. This is an impressive roster, but there are a lot of injury concerns in the lineup. And like any team, they cannot afford to lose arms from the rotation. Key bullpen pieces Brash and Santos are already dealing with injuries to start the year.

If the Mariners can stay relatively healthy, this team can win the AL West. They finished just two games behind the Astros and Rangers last year with a lesser roster that played uninspiring baseball through the first half. This team has only improved, while Texas has done next to nothing over the offseason. Seattle already went 9-4 against Houston last season. 

The division will be extremely competitive, but the Mariners are not far off at all. The 2024 season should be another very exciting year for baseball in the Pacific Northwest.

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