Manny Acta, Kevin Seitzer among Mariners coaches not returning for 2026

What happened

MLB.com reported that Mariners bench coach Manny Acta and hitting coach Kevin Seitzer will not return to Seattle's coaching staff for the 2026 season. The departures extend a significant organizational reset that has been unfolding in the days since the regular season concluded.

The news arrives in the immediate wake of the club's decision to dismiss manager Dan Wilson — a move Mariners GM Jerry Dipoto addressed publicly, taking personal accountability for the direction of the franchise and announcing a formal managerial search. The coaching staff changes reported by MLB.com represent the next layer of that reconstruction, with two of the most prominent voices in the dugout now set to move on.

Why it matters

Bench coaches and hitting coaches occupy two of the most operationally consequential roles on any major league staff. The bench coach functions as the manager's closest in-game collaborator — the person tracking lineup matchups, bullpen availability, and situational decisions in real time. The hitting coach, meanwhile, is the primary architect of the offensive development environment, working daily with hitters on approach, mechanics, and preparation.

Acta brings a profile that extends well beyond the bench role. He previously managed at the major league level, which means Seattle is losing not just a bench coach but someone with managerial experience — a resource that tends to be in high demand precisely when a club is conducting a managerial search. Seitzer, for his part, has a long track record in player development and hitting instruction across the league.

The timing is worth noting. The Mariners are currently conducting a search for a new manager, with Torey Lovullo emerging as a leading candidate per earlier Posterior Wire reporting. Whoever takes that job will, in all likelihood, have meaningful input into who fills the coaching roles around them — which makes the departures of Acta and Seitzer less a closing of doors and more a clearing of the table before the next conversation begins. The new manager inherits not just a roster but a staff-shaped blank canvas, which is either an opportunity or a very long to-do list, depending on how you look at it.

The numbers

Seattle finished the 2026 season at 76-86 (.469), landing third in the AL West and 5 games back in the division. The club ranked 9th in the Wild Card standings, 8.0 games relative to the cut line, and was eliminated from both the division race and Wild Card contention before the season ended. The Mariners did close on a two-game winning streak — the kind of detail that reads differently in October than it would in July, but a detail nonetheless.

A 76-86 record is the organizational backdrop against which every personnel decision this offseason will be evaluated. It is the number Dipoto cited when he addressed accountability publicly, and it is the number that made the managerial change — and now these coaching departures — feel less like a surprise and more like an inevitability that had been penciled in since sometime around late August.

Where the club stands

The Mariners finished 76-86 (.469), third in the AL West. They enter the offseason having already dismissed their manager and now parting ways with at least two prominent members of the coaching staff per MLB.com. The managerial search is active, with Dipoto having announced it publicly in the days leading up to this report.

The organizational picture, then, is one of deliberate reconstruction at the leadership level. The field staff that guided Seattle through the 2026 season is being substantially reconstituted, and the shape of the coaching staff going forward will depend in meaningful part on who is ultimately hired to manage the club. That is the sequence: hire the manager, then build the room around them. Seattle appears to be following it in order.

What we don't know yet

MLB.com's report identifies Acta and Seitzer as coaches not returning, but the full scope of staff changes has not been detailed. It is not yet known which other coaches, if any, will or will not return. The managerial search remains ongoing, and no hire has been announced.

It is also not yet clear what role, if any, the incoming manager will play in shaping the rest of the coaching staff. That is standard practice around the league — new managers typically have input into their staffs — but it has not been reported as a specific condition of Seattle's search. The distinction matters: a manager who builds their own staff from scratch is working a different job than one who inherits most of it.

What to watch

The managerial hire is the load-bearing decision. Once Seattle identifies its next manager, the coaching staff picture will begin to clarify — who that person wants as a bench coach, who they trust to run the hitting room, and how much of the existing staff, if any, carries over. Dipoto's public accountability statement and the active search suggest the club is moving with some urgency, so the timeline on that front is worth monitoring closely.

Separately, Mariners prospect Kade Anderson was named the 2026 Pitching Prospect of the Year after a standout minor league season, per earlier Posterior Wire reporting. The development pipeline has something to offer the next staff — whoever that staff turns out to be. A 76-86 season tends to concentrate minds on the major league product, but the minor league infrastructure is part of what the incoming coaching group will be working with and working toward.

The Acta and Seitzer departures, reported by MLB.com, are the latest data points in what is shaping up to be a thorough offseason overhaul in Seattle. The 76-86 season is over. The work of assembling the people who will try to change that number is underway.