Mariners' rumored interest in slugging Giants prospect feels too good to be true

It has felt for weeks now like the Seattle Mariners just keep getting connected to the same names over and over again. But now comes a new one that feels totally out of left field, so you'd better brace yourselves: Bryce Eldridge.

We have the San Francisco Chronicle to thank for this. Shayna Rubin reported early on Sunday that the San Francisco Giants aren't leaving Eldridge off the table in trade talks. Susan Slusser followed up with two teams that are known to have interest in him: the Boston Red Sox and the Mariners.

Mariners' reported interest in slugging Giants prospect feels too good to be true

Though Eldridge isn't a household name along the same lines as Ketel Marte or even Brendan Donovan, prospect hounds will know him. He ranks as the No. 12 talent in the league for MLB Pipeline, mostly owing to his 70-grade power from the left side of the plate.

Even at 21 years old, Eldridge doesn't need more seasoning in the minors. He slashed .260/.333/.510 with 25 homers in 102 games across three levels this year before making his debut with the Giants on September 15. He's set to enter 2026 in a first base/DH time share with Rafael Devers.

Now, the Giants keeping Eldridge on the table for a potential trade is not the same as shopping him. Yet having both him and Devers — i.e., power-first lefty hitters with questionable defensive value — is perhaps redundant, and the Giants have pressing needs in their starting rotation and in their outfield.

This, also, is where the potential for a trade with the Mariners begins to break down.

Slusser brought up Luis Castillo and Randy Arozarena as possible trade chips for Seattle, but neither is going to fetch Eldridge in a one-to-one swap. Castillo is in his post-prime era, with two years and nearly $50 million left on his contract. Arozarena is projected to make $18.2 million in 2026, which is also his last year before free agency.

There are other paths the Mariners could take to Eldridge, of course. They could package Castillo with one or more prospects, or perhaps offer an alternative package headlined by another starter, such as Logan Gilbert, George Kirby, Bryce Miller or even Bryan Woo, if they were so inclined.

Yet even in starting this conversation, we're wading into murky waters. All signs point toward the Mariners wanting to keep their current starting five together. And even if they were willing to break it up, is Eldridge the right guy for that kind of risk?

With Josh Naylor locked into first base for the next five years, the Mariners would trade for Eldridge either knowing he'd strictly be a DH, or with plans to move him to right field. They'd be risking a failed experiment with the latter, as the 6-foot-7, 240-pound former pitcher has the arm for right field, but is not much of a runner. And even if the Mariners were fine with Eldridge as a full-time DH, that would mean taking a lot on faith.

His upside is enormous, but it is strictly hypothetical for now. He's only played 10 games in the majors, and those weren't exactly impressive. In 37 plate appearances, he recorded three hits and struck out 13 times.

It would make more sense for Eldridge to come to Seattle in a prospect-for-prospect swap, perhaps one involving a pitcher such as Kade Anderson, Jurrangelo Cijntje or Ryan Sloan. Yet while those are the best arms in Seattle's system, none is going to be MLB-ready sooner than midway through 2026. The Giants need rotation help now.

In all, this concept is best filed under "Interesting, But Complicated." And that might even be putting it generously, as the Mariners and Giants working out a fair trade involving Eldridge might just be plain unworkable.