Where can sailors go for help at third base?

The Mariners haven’t been shy about their desire to bolster their infield mix this winter, and while the club has shown interest in improving at second at points in the offseason, their focus appears to be primarily on improving the internal corners rather than on the keystone, where options such as Dylan Moore AND Ryan Bliss available to hold down the forte until the upper and central internal perspective Cole Young is ready for his MLB debut.

First base appears to be a fairly simple hole for the bat to fill. They have long been linked to a reunion with the veteran Justin Turnerwhich helped strengthen their first base mix down the stretch and could pair well with Luca Raleyhe is the left-handed bat at the position. Aside from this possibility, a number of valid options for veterans such as Marco Canha AND Antonio Rizzo they still remain available even in free agency, not to mention trade candidates like Yandy Diaz, Luis Arraez and Monte Wade Jr. which could provide a slightly greater impact at the expense of commercial capital. Even after a rush on first base talent just before the new year, there remain plenty of options available for the club to consider as they look for an upgrade for Raley and the young Tyler Locklear.

Third base, however, is a little more complicated. While a number of players could at least theoretically be available for the position this winter, Alex Bregmann AND Nolan Arenado both appear to be well out of the Mariners’ price range. Another potential trade candidate, Eugenio Suarez, also seems unlikely to be a fit given that the Mariners themselves traded Suarez just one offseason ago. Other than Bregman, few options available in free agency provide obvious upgrades Josh Rojaswho the club used at third base last year before not featuring him in November.

Even standing doesn’t seem to be an option in this position: Austin Shenton AND Leone Rivas he could at least theoretically slot into that position, but have a total of 136 plate appearances at the big league level, requiring at least one veteran addition to take the lion’s share of reps at the hot corner. With a seemingly tight budget and few internal solutions available, who could be a realistic target for the club this winter?

Free agents

• Ha-Seong Kim: Kim, 29, is arguably the best free agent infielder who could potentially fit within the Mariners’ budget given his 106 WRC+ and defense across the infield over the past three seasons. MLBTR expected Kim to get a relatively affordable one-year, $12 million deal before the 2025 season at the start of the offseason, but as the market developed some reports indicated he could get a multi-year deal done this winter and, Depending on how the deals go, it’s easy to imagine things going beyond Seattle’s comfort zone. Regardless of the possibility of Kim reaching a deal that goes beyond what Seattle is willing to offer, Kim has played both shortstop and second base much more commonly than third base throughout his career. With Kim likely trying to rebuild his value after shoulder surgery, it would hardly be a shock if he would rather sign somewhere where he would be able to be a regular shortstop. He would be a defensive upgrade for JP Crawfordbut the Mariners have shown no desire to move him from the position to this point.
• Paolo De Jong: DeJong, 31, was a quality starter at shortstop with the Cardinals early in his career and even made an All-Star game in 2019. His offense declined greatly after that season, however, and he struggled to a 72 wRC+ from 2020 to 2023. Last season, however, was something of a rebound for the veteran, who split time between the White Sox and Royals and managed to reach a respectable .227/.276/.427 (95 wRC+) in 139 games with solid glove work at both shortstop and, more importantly in this context, third base. That respectable season should allow him to easily beat the $1.75 million guarantee he got with Chicago last winter, though he should still be a perfectly affordable option for the Mariners this winter. It’s easy to imagine that DeJong would jump at the opportunity if he were offered regular starts in Seattle, but it’s fair to wonder if the Mariners would have much interest in him as a fit. After all, they just parted ways with Rojas in November despite doing a great job with his below-average offense, and DeJong’s 32.4% strikeout rate last year goes against the more contact-oriented approach that the club has attempted to cultivate in recent years.
• Yoán Moncada: Moncada would be an interesting candidate for the third base job in Seattle. A former top prospect, Moncada had an up-and-down career with the White Sox before things went off the rails due to injuries in recent years. He’s only played 104 games over the last two seasons, but he’s posted a pretty respectable 101 wRC+ in that time. It’s far from impossible to imagine him returning to something closer to the 120 WRC+ he posted with Chicago in 2021, though it’s possible that (as with DeJong) his high strikeout numbers throughout his career could lend some truce for the Mariners. That said, Moncada’s overall offensive profile when healthy is stronger than DeJong’s, and given his limited track record in recent years, the infielder should still be very value for money.
• José Iglesias: Iglesias is coming off a career year with the Mets that saw him slash .337/.381/.448 (137 wRC+) in 291 plate appearances in 85 games. That’s the kind of performance that should make him a very attractive candidate for just about any club’s bench, but the Mariners could stand out among other potential suitors by offering him a regular role. That said, there are many potential reasons for concern in Iglesias’ profile. The veteran infielder will play all of next season at age 35, and it’s impossible to imagine him replicating the incredible .382 BABIP that made him an above-average hitter last year. He’s also fairly inexperienced at third base, although he played the position quite well (+2 outs above average) when called up by the Mets last year. Iglesias’ contact-oriented approach could have particular appeal in Seattle, and he could be an interesting option for the club if it’s interested in giving expanded roles to youngsters like Shenton and Rivas.

Commercial candidates

• Alec Bohm: Bohm also stands out on this list because the club has reportedly already expressed interest in his services this winter. Those talks understandably seemed to fizzle out when the Phillies asked Logan Gilbert OR George Kirby in exchange for Bohm’s services, but if Philadelphia decides to lower its asking price as the offseason drags on, he remains one of the best options available to the Mariners this winter. While Bohm’s defense at the hot corner has generally left much to be desired, last year he posted a strong .280/.332/.448 (115 wRC+) and hit just 14.2% at times, making him a prime candidate for a club that has typically moved away from tall hitters whenever possible. If the asking price for Bohm remains close to what it was at the start of this offseason, however, it’s hard to imagine a trade happening.
• Willi Castro: Castro, 28 in April, has started only 48 games at third base in his entire career, but he is a very utility player with plenty of experience at both shortstop and second base, which suggests he should be can handle the hot corner with relative ease. Since joining the Twins prior to the 2023 season, Castro has had 108 consecutive wRC+ seasons while accumulating 5.6 fWAR. Minnesota seems disinclined to pay the $6.2 million that MLBTR contributor Matt Swartz projects Castro will earn in his final trip through arbitration, but that’s a price the Mariners should have no trouble swallowing for a probable regular player in a position of need.
• Brett Baty: Baty, 25, stands out from the other potential trade candidates mentioned thanks to the fact that he only has 169 MLB games under his belt. Baty, a former top-30 prospect in the sport, has struggled to this point in his major league career and hit just .229/.306/.327 (83 wRC+) in 50 games with the Mets last season. The emergence of Marco Vientos has seemingly ruled Baty out of the path to play for the club in 2025, especially if Pietro Alonso he eventually returns to Queens. This could make Baty expendable for the club, and if the Mariners are unable to find a more reliable veteran option in free agency or on the trade market, it would be very understandable for the club to pivot towards rolling the dice on a player with The Baty’s attacking potential and his pedigree.