The Mariners have spent enough time waiting for talented hitters to figure it out. Also, at some point, the people handing out the assignments need better answers, too. That’s what makes Jason Kanzler’s arrival interesting. Seattle officially hired its new manager Tuesday, putting a consequential piece of this team’s future in his hands. The Mariners’ announcement makes the appointment official. And for those looking for some historical success, his work with Jeremy Peña gives us something to like.

We can get somewhere with that example. A struggling hitter, a specific adjustment and an explanation of how it helped. That’s just one of the starting points that mean more than a speech about trusting the process.

Seattle went 76-86, and several of its most important hitters regressed. Julio Rodríguez and Cal Raleigh were among the players whose disappointing seasons helped sink an offense that scored the third-fewest runs in baseball. There’s plenty of work waiting for Kanzler.

Jeremy Peña Gives Us a Reason to Buy Into Jason Kanzler

During Peña’s rookie season in Houston, opposing pitchers found ways to exploit him. Breaking balls became a problem, and the early excitement gave way to the familiar grind of a young hitter trying to catch up with the league.

In September 2022, Peña reduced his pronounced leg kick, getting his front foot down earlier. He said the change gave him more time to see the pitch and decide whether to swing. Kanzler, working on Houston’s coaching staff, described improvements in Peña’s contact, handling of sliders and confidence.

Kanzler’s involvement in Peña’s development offers an encouraging example of that work. Peña went on to win ALCS and World Series MVP honors that fall. Those awards belong to the player, and Houston had other people contributing to his success. That’s the kind of clarity that Seattle could benefit from.

The Mariners Need Answers Their Hitters Can Use

Seattle’s problems are specific enough that we can put some expectations on this hire. In August, Adam Jude reported that Julio Rodríguez was chasing 41.3 percent of pitches outside the strike zone. Cal Raleigh’s chase rate had climbed from 31.8 percent  in 2025 to 36.2 percent at that point in 2026. Kevin Seitzer described Raleigh struggling to sync his swing after an oblique injury, with pitchers exploiting his willingness to chase elevated fastballs.

That gives Kanzler and his hitting staff somewhere to start with the veterans. Peña’s example is important here because it connects those two problems. Getting into position earlier gave him more time to read the pitch. That’s a coaching intervention we can understand. Seattle needs to find its own version of that answer for hitters whose decisions deteriorated alongside their swings.

And the organization has already admitted that some of its instruction went sideways. Kanzler will be paired with CJ Gillman who’s taking over as the Mariners hitting coach. Gillman coordinated Seattle’s minor league hitting instruction from 2022 through 2025. His return gives Kanzler access to someone who knows what those players were taught and why. The first assignment should be comparing that work with what changed in Seattle.

For Cole Young and, as he advances, Colt Emerson, that review has real consequences. But it could also lead to a positive turn in production. We know Kanzler’s specialty, but he’s being asked to do so much more. He also has to make sure that the Mariners survive other things, like a losing streak. It’s easy to endorse a development plan. But he’s also the manager.  He has to keep the instruction focused while deciding whether that player needs another start, a narrower role or more work in the minors.

The front office has a responsibility in that equation, too. Adding dependable offense would give Seattle more room to develop their young guys. That’s where the Peña connection should take us. It gives the Mariners an example of Kanzler helping a hitter make a useful adjustment. Now Seattle needs him to build a staff that can deliver that help consistently, and stop losing the lessons somewhere on the road to T-Mobile Park.