Mariners could be on a collision course with an impossible decision at second base

The Seattle Mariners keep trying to sell fans on a future where everything lines up cleanly: the next wave arrives on schedule, payroll stays tidy, and the infield sorts itself out like it’s following a blueprint.

And then Michael Arroyo shows up and completely shreds the blueprint.

MLB Pipeline just dropped its top-10 second base prospects for 2026, and Arroyo is sitting No. 2 in all of baseball at the position. That could be completely hijacking someone else's timeline. If you’re the Mariners — a team that loves a clean plan — that’s where the tension starts.

Michael Arroyo is forcing an uneasy Mariners conversation about Cole Young

Seattle is still high on Cole Young. The organization (and plenty of the coverage around it) keeps circling back to Young as the sensible, ready-made solution at second base. But Arroyo doesn’t care what the Mariners planned.

Arroyo’s profile screams “fast-tracked problem.” He’s compact strength, loud contact, and plate discipline. MLB Pipeline notes that he cut his strikeout rate in 2025 (18.7 percent) while still living in the walk lane (12.4 percent), and he’s got real impact juice (40 homers the last two years) plus sneaky value on the bases (30 steals in two seasons). 

Let’s play this out: What if Young breaks camp as the starter at 2B and looks… fine? Not a star, but steady. And then what if Arroyo rakes in the high minors and sparks the question “why is this guy still down there?”

Now you’re on a collision course. Because the hardest decisions aren’t “who starts?” It’s who becomes the organization’s priority when both answers look legitimate, and the fanbase can see the better upside sitting right there.

Seattle’s already experimenting with Arroyo in left field, which tells you the Mariners understand the logjam risk. But that solution only works if the big-league outfield actually has oxygen. And for the time being, left field is pretty spoken for — meaning the “just move him” escape hatch might be more wishful than real.

This is the kind of internal competition teams say they want. But it also exposes a very specific nerve: when two young options emerge, do they actually pick the one with the higher ceiling… or the one that keeps everything simplest and cheapest?

If Arroyo spends 2026 banging on the door the way his track record suggests, the Mariners might not get to slow-play the situation. They might have to make an “impossible” call at second base sooner than they’d like — and Mariners fans should be hoping iron sharpens iron and Arroyo forces their hand.