We’re about to break the first two rules of talking about roster depth, which is that you do not talk about a team being too deep in any given area. Yet so it seems with the Seattle Mariners and their infield depth, which goes so far down that you’ll find the wreck of the Titanic if you scroll for long enough.

Josh Naylor and J.P. Crawford are the only surefire starters on the 2026 infield as of now, but the Mariners will have no fewer than five players jockeying for the other two spots in the spring. Ben Williamson and Colt Emerson will battle for third base, and there will be Cole Young, Leo Rivas and Ryan Bliss vying for second base even if the Mariners fail in their quest to bring back Jorge Polanco.

It’s a tough thing to look up and see if you’re a Mariners infielder who’s nearing major league readiness, but isn’t there just yet. And until now, nobody matched that description like Michael Arroyo.

Plot twist: Michael Arroyo’s new position opens up a new path to Mariners stardom

Ranked by MLB Pipeline as the No. 63 overall prospect in the league, Arroyo has only played on the infield since he signed with the Mariners in 2022. He’s played some at shortstop and third base, but mostly at second base to the tune if 206 total starts in four seasons in the minors.

It was notable, then, when Arroyo was spotted as the starter in left field for the Caimanes de Barranquilla of the Colombian Winter League on Saturday. And that may not be a one-off, as Adam Jude of The Seattle Times reported on Wednesday that the Mariners project the 21-year-old as a left fielder in the future.

As much as this feels like it’s coming out of nowhere, it has made sense for a while now. Arroyo is seen as having merely average arm strength and footspeed, and left field tends to be the best place for guys like that — at least in MLB’s post-shift era, in which second basemen have to actually cover ground again.

What was always true no matter his defensive position is that Arroyo’s bat will ultimately determine his place in the major leagues. And right now, his stick might even be underrated. He has a .408 OBP to show for his minor league career, and he’s cracked 40 homers over the last two seasons.

Michael Arroyo goes off the light pole 💣 pic.twitter.com/OaYEIOtrGF

— Mariners Player Development (@MsPlayerDev) May 27, 2025

The more you can picture Arroyo as a left fielder, the more that life after Randy Arozarena in Seattle comes into focus. The two-time All-Star has been good for the Mariners, but he’ll be a free agent after 2026 and then potentially in line for a nine-figure deal. Arozarena already looks vaguely like a trade candidate, so him somehow sticking with the Mariners beyond 2026 is hard to fathom.

Given that he made it to Double-A in 2025, Mariners fans should get their first glimpse of Arroyo sometime in 2027. The same is also true of slugging right field prospect Lazaro Montes, which makes it possible to daydream about the Mariners having an almost entirely homegrown lineup in the near future:

Michael Arroyo, LFCal Raleigh, CJulio Rodríguez, CFJosh Naylor, 1BLazaro Montes, RFColt Emerson, SSHarry Ford, DHCole Young, 2BBen Williamson, 3B

Granted, maybe this is less daydreaming and more wishcasting. But at least it’s plausible, which makes for an upgrade on Arroyo looking like a second base prospect without a clear path to playing time.