Mariners’ Pitching Depth Could Cost Them a Valuable Triple-A Insurance Arm

Seattle’s depth could cost it a legitimate Triple-A insurance arm.

Seattle Mariners pitcher Randy Dobnak (67) throws a pitch in the first inning of a Cactus League game between the Cincinnati Reds and Seattle Mariners, Sunday, Feb. 22, 2026, at Goodyear Ballpark in Goodyear, Ariz. | Frank Bowen IV/The Enquirer / USA TODAY NETWORK via Imagn Images

The Mariners have a known commitment to developing and finding impact arms. At some point, though, having that much pitching stops being such a clean luxury. Randy Dobnak might be the latest example of what happens when you have too much solid pitching depth.

Dobnak’s minor league deal with the Mariners includes a June 15 upward mobility clause. Once that date arrives, Dobnak can force the Mariners to add him to their own 40-man roster or trade him to the team willing to make room. If no team steps up, then nothing changes and Dobnak stays in the Mariners’ system.

It’s not a development that could shake the franchise. But it does reveal where the Mariners are at right now. Dobnak’s 4.50 ERA with Triple-A Tacoma isn't flattering. But the Pacific Coast League also isn’t the most pleasant place for arms. Just look at what happened in Las Vegas on June 8. The Brewers and Athletics hit a combined 11 home runs and scored 29 runs in a PCL ballpark. 

So with Dobnak, you have to look at more realistic numbers that make him appealing. Which is a Triple-A-best 59.9 percent ground-ball rate among qualified pitchers.

This is the type of arm every contender wants sitting one phone call away. He can cover innings and keep the ball on the ground. To the Mariners, that translates to a Cooper Criswell replacement if needed. Meaning Dobnak can be valuable and still be expendable at the same time.

Randy Dobnak Shows the Cost of Mariners Having Too Much Pitching

This is just the price of being good at something. Pitching development is the Mariners organizational personality. When the big-league staff is healthy, they’re usually fine. And when the system has extra arms, it looks even better. But eventually, those arms are going to want an  opportunity. Minor league depth is only depth until another team is willing to offer a faster path to the majors.

Dobnak is not really the M’s problem. Roster space is. Seattle has to ask whether it can afford to lose the kind of pitcher every team eventually needs at some point during a long season.

If another club does come calling, this becomes a revealing test of how much Seattle values its own depth.

This is also a team that could be active in the bullpen market at the trade deadline, which makes the air around Dobnak even more interesting. If the Mariners are already looking at struggling players on the 40-man roster, or if a player needs to be transferred to the 60-day IL to clear space, they have less than a week to sort that out.