Just over a month out from the MLB trade deadline, the Seattle Mariners currently sit in first place in the AL West despite one of baseball’s worst offenses, holding a 6.5-game lead thanks to an incredibly talented pitching staff and disappointing seasons from their division rivals, the Texas Rangers and Houston Astros. Both Texas and Houston — the last two World Series champions — are far too talented to count out, even with records sitting under .500, and will both be looking to buy at the deadline in addition to the pieces they hope to return from the injured list. If the Mariners truly want to capitalize on this window, they will need to add bats at the deadline to supplement their subpar offense and complement their elite rotation.
Since their first year of playoff contention in 2021, the Mariners have consistently relied on an unbalanced combination of offense and defense to win games, hoping that their pitching can limit opposing offenses so that they can win close games late. Since the start of 2021, Seattle ranks 24th in baseball with a collective .704 OPS, making them one of just two teams in the bottom 10 — along with Cleveland — with a record over .500. Additionally, during this time, the Mariners lead all teams with 5,186 strikeouts, 154 more than the second place Cubs. This comes in contrast with a pitching staff that has been one of baseball’s best — ranking eighth in ERA — and has continued to get better with the call-ups of Logan Gilbert, George Kirby, Bryce Miller, and Bryan Woo as well as the 2022 trade deadline acquisition of Luis Castillo.
It’s been the same story this year in Seattle, with an offense that ranks 24th in OPS, 27th in runs per game, and first in strikeouts and a pitching staff that ranks seventh in ERA, first in WHIP, and 10th in strikeouts. This lackluster offense has been compounded by a disappointing season from star center fielder, Julio Rodríguez, who posted a 136 OPS+ across his first two seasons but has seen that number drop to 98 in 2024, below the league-average mark of 100.
This disparity can be seen distinctly through Seattle’s draft strategy. From 2018-2020, the Mariners selected Gilbert, Kirby, and Emerson Hancock — all of whom have developed into major league starters for the club — before taking Miller and Woo in the fourth and sixth rounds of the 2021 MLB Draft, respectively. As that pitching talent developed and reached the big leagues, Seattle shifted its draft strategy toward position players, selecting catcher Harry Ford with the 12th pick in 2021, shortstop Cole Young with the 21st pick in 2022, and shortstop Colt Emerson, outfielder Jonny Farmelo, and shortstop Tai Peete with the 22nd, 29th, and 30th picks in the 2023 draft, respectively.
The Mariners’ excellent drafting and player development have netted them one of the deepest selections of minor league hitting talent in all of baseball. Seattle’s top 11 prospects per MLB Pipeline are all hitters, with four of them landing in the top 100: No. 26 Young, No. 27 Ford, No. 49 Emerson, and No. 82 Lazaro Montes, a 2022 international amateur free agent signee from Cuba. Additionally, Farmelo recently debuted at No. 49 on Keith Law’s latest top 50 prospect rankings for The Athletic along with No. 36 Felnin Celesten, a switch-hitting Dominican shortstop who MLB Pipeline ranked as the No. 2 player in the 2023 international amateur free agent class.
For the most part, all of the Mariners’ top hitting prospects have mashed this season, with 2022 second-round pick Tyler Locklear even reaching the bigs to supplant an injured Ty France and hitting his first home run on June 13. Although it may be tempting to wait for these talented position players to reach the majors, the majority of them are still a ways away, with Young and Ford currently playing for AA Arkansas, Emerson, Montes, Peete, and Farmelo playing for A- Modesto, and Celesten still playing rookie ball in the Arizona Complex League.
Time to wait for prospects is something the Mariners do not have right now. The elite five-man rotation of Castillo, Kirby, Gilbert, Miller, and Woo has absolutely eviscerated major league hitting this year, giving Seattle the most innings of any starting rotation with the fifth-lowest ERA. Currently in first place, they have a chance to win the AL West for the first time since 2001 and have a rotation that no team wants to see in a playoff series. In addition to an offensive boost, the Mariners will also need to add bullpen arms to a group that has been ravaged by injuries to key relievers Matt Brash and Gregory Santos, placing a large burden on the shoulders of closer, Andrés Muñoz. From 2021 to 2023, the Mariners ranked sixth in baseball with a 3.58 ERA from their bullpen but have seen that ranking drop to 12th this season.
The best bats potentially available at this year’s trade deadline include the Blue Jays’ Vladimir Guerrero Jr., the White Sox’s Luis Robert Jr., and the Mets’ Pete Alonso. Guerrero is the least likely of the three to be moved, with Blue Jays GM Ross Atkins recently saying “It just doesn’t make any sense for us” to trade either Guerrero or shortstop Bo Bichette with the team only 4.5 games out of the wild card at 33-36. Guerrero has one more year of arbitration before hitting free agency in 2026 at 27. With a year and a half left of team control and Guerrero heating up by slashing .324/.404/.458 since May 1, it would likely take multiple of the Mariners' top 100 prospects to get him. He has yet to live up to the lofty standards he set for himself as the 2021 AL MVP runner-up at the age of 22, but is still one of the most talented hitters in baseball and would be a massive addition if Seattle could pull it off.
Robert recently put on a show in Seattle as the White Sox dropped three of four games against the Mariners, launching three homers in the series. Robert signed a team-friendly deal with Chicago before making his much-anticipated debut as MLB Pipeline’s No. 3 prospect in 2020, making $12.5 million this year, $15 million next year, and with club options for $20 million in both 2026 and 2027. There’s no denying his talent, clubbing 38 homers last season while posting a career OPS+ of 125, but he has struggled to stay on the field, missing almost all of April and May this year and averaging just 104 games from 2021-23. Additionally, he plays a style very similar to that of Rodríguez, with an aggressive approach leading to many strikeouts with very few walks. At only 26 years old, he’s only likely to be moved because of the absolute dumpster fire that is baseball on Chicago’s south side and would require a similar package to Guerrero, with his injury concerns offsetting the additional two years of team control.
Alonso is the most guaranteed of the three to be traded as the Mets sit six games under .500 and in fourth place in the NL East. The Polar Bear will be a free agent at the end of the season and would provide some much-needed pop into any lineup, leading all players with 206 home runs since his 2019. This could end up being a true rental as there has been reported interest in a reunion with the Mets even if Alonso were to be dealt, meaning the prospect haul they would receive in return would be significantly less than the asking prices for Guerrero and Robert.
Some other options that Seattle could potentially look to add to their lineup include the Athletics’ Brent Rooker and the Angels’ Taylor Ward as corner outfielders and the Cardinals’ Paul Goldschmidt and the Marlins’ Josh Bell at first base. Rooker experienced a late breakout last season, making his first All-Star game at age 28, and will enter his first year of arbitration at the end of the season but is limited defensively, starting 43 games this year at DH. Ward has two years of arbitration remaining and has posted a 118 OPS+ since 2021. Goldschmidt will be a free agent at the end of the season and is only two years removed from the 2022 NL MVP but has shown significant signs of decline at the age of 36, posting career lows across the board. Bell is also an impending free agent and has been traded at each of the last two deadlines — first from the Nationals to the Padres and then from the Guardians to the Marlins — while posting a career 116 OPS+. These shouldn’t be the Mariners’ main targets, but are names to be kept in mind if Guerrero, Robert, or Alonso end up off the table.
My top target for the Mariners is Guerrero. It will take a haul to get him but his bat would add juice that the lineup has severely lacked and could help push the Mariners over the edge into true World Series contention. The only prospects who are off the table for me are Celesten — who holds the highest overall potential in the entire system — and Montes — who currently leads all minor leaguers under the age of 20 in on-base percentage, slugging, OPS, hits, homers, RBIs, and total bases. Every other prospect should be on the table for Guerrero. For Robert, I would be reluctant to include Emerson — who Keith Law recently moved up to 10th in his latest top 50 prospect rankings — and would be adamant to only give up one of either Young or Ford. Alonso would require a smaller deal, with projected trades including names like France and Hancock.
Whichever way Seattle ends up going at the deadline, this is shaping up to be one of the most exciting Mariners teams of the 21st century and a major addition could potentially take them over the top to reach their first-ever World Series.