Jeff Passan kicks the hornet's nest with Mariners starting pitching trade concept

The Mariners are going to have a surplus of starting pitchers when Bryce Miller is healthy, and one way to resolve that would be to go to a six-man rotation. Or, they could look to trade Logan Gilbert or Bryce Miller.

It's not our idea. It comes from ESPN's Jeff Passan, who floated it during his regular spot with Seattle Sports’ Brock and Salk on Tuesday. Though each has been a mainstay in the Mariners' rotation for years now, Gilbert is set to hit the free agent market after 2027, with Kirby following after 2028.

Hence why, in Passan's words, "you wonder if one of these guys who’s been as seminal as both of them have to this rise of the Mariners is going to suddenly become a potential trade candidate.”

The Mariners trading Logan Gilbert or George Kirby feels like a third rail

The other thing the Mariners could do, of course, is extend Gilbert and/or Kirby. There's been some buzz about that possibility recently, and it's not as if Jerry Dipoto is gun shy when it comes to extensions — quite the opposite, really.

However, it's an "easier said than done" situation with both.

Given how close he was to free agency at the time, the Mariners' five-year, $108 million deal with Luis Castillo from 2022 is hypothetically a model for Gilbert or Kirby. But that one is also an outlier among their recent extensions, which have mostly consisted of aiming below market value to secure Cal Raleigh, Julio Rodríguez and now Colt Emerson.

Meanwhile, the Mariners can be confident that the long-term replacements for Gilbert and Kirby are already in the organization. Ryan Sloan and Kade Anderson, who rank as the No. 22 and No. 23 prospects in MLB for Baseball America, could even be ready as soon as this year.

Also meanwhile, the Mariners have major problems on offense. The slow starts of Raleigh, Rodríguez and Josh Naylor are surely unsustainable, yet other flaws — such as continued poor production from right field and designated hitter — could require action.

In theory, this is where a trade of Gilbert or Kirby could come in. And despite their proximity to free agency, both have obvious value as proven top-of-the-rotation starters. Just on his own, each is worthy of a big bat.

In practice, though, the possible threat to clubhouse harmony isn't the only thing that could preclude a trade of Gilbert or Kirby. There's also the matter of practicality. Typically, sellers on the trade market aren't looking for short-term assets. Likewise, buyers typically aren't looking to subtract key pieces from one part of their roster just to add to another part. It's like robbing Peter to pay Paul.

Besides which, the Mariners just have never seemed interested in trading a starter under Dipoto. If anything, they've been downright resistant to the idea.

So yeah, this whole concept should be filed under "I'll Believe It When I See It" at least until the winter, when all bets are going to be off ahead of a potentially ugly labor fight and subsequent work stoppage.