It started in late March with a 4-2 win over the Athletics at home. It ended 173 games later in late October in Toronto, concluding the longest season in Seattle Mariners history.
There was an April surge, a swoon through May and June, a highly impactful trade deadline in July. There was an August and September surge that brought pennant-race baseball to Seattle and landed the M’s an AL West title. Then there was the AL Division Series victory and coming so tantalizingly close to ending the franchise’s World Series drought.
Along the way, Cal Raleigh became a household name across sports. Josh Naylor turned immediately into a fan favorite after his July arrival. The Eugenio Suárez reunion became a success with one big October swing. Bryan Woo turned into an ace. Julio Rodríguez flipped the switch in July and became one of the best players in the league.
And there was that one seventh inning in Toronto everyone would like to have turned out differently.
Here are five things we learned about the Mariners in 2025.
Big Dumper’s world
Junior. Ichiro. Dumper.
Think for a moment about a time when the entire baseball world cared the most about a player wearing a Mariners uniform. There are only a few.
It happened for most of the 1990s with Ken Griffey Jr. Whether it was the backward hat, the electric smile or the prettiest left-handed swing ever seen, Griffey was the coolest player in the game.
It happened in 2001 when this relatively unknown entity in North America arrived from Japan and by the end of his rookie season had collected an MVP award and no longer needed to go by his full name. He was Ichiro.
And it happened again in 2025 – it was Big Dumper’s world and everyone was along for the ride.
What we saw from Cal Raleigh was an accentuation of pieces that had flashed in previous seasons but came together in a combination that could lead to just the third AL MVP in franchise history.
We had seen his durability before, but not like this. We have seen the power, but never to this level. We have seen the potential as a right-handed hitter, but not with this consistency.
And we have seen Raleigh be a leader. But this season, the Mariners became his team, even if it was a collective effort.
“I think about Cal and how far he’s come since he came to the big leagues and where he is now. I mean, he’s the MVP of the league and that’s a big distance,” Mariners GM Justin Hollander said. “He’s come and he’s done it through will and work and determination.”
Whether Raleigh can replicate this again is one of the big questions going into 2026. But that is a question for the future. For now, enjoy that we likely saw the best season ever from a catcher and it may never be matched.
Julio is what Julio is
Julio Rodríguez is not going to start great. There is enough track record over his four seasons in the majors that it should not be any sort of surprise. March, April and May are going to be quiet at the plate and by the time September rolls around, we are going to be talking about Rodríguez finishing in the top 10 of MVP voting.
That has been the script of his previous seasons and 2025 was no different.
Except, while Rodríguez suffered through a slow start at the plate – although statistically it was the best first couple months of his career – his defense was exceptional from game No. 1.
That was the difference this season. Even when the bat was sluggish, the defense never languished. He is a Gold Glove finalist and in any other year probably would win; Boston’s Ceddanne Rafaela seems to be the clear favorite this season.
Of course, everyone would love it if Rodríguez’s first three months with the bat looked like his last three. Over the first 81 games in 2025, Rodriguez hit .255 with a .724 OPS, 11 homers, 12 doubles and 42 RBI. Over the final 81 games, Rodríguez was .280 with a .874 OPS, 19 doubles, 21 homers and 53 RBIs.
He was nearly a 7-win player by Baseball-Reference WAR (a tool measuring how many wins a player adds over a replacement-level player) and nearly a 6-win player by FanGraphs WAR. He will be a top 10 finisher in the AL MVP balloting.
If he ever does put together a first two or three months that rivals what he has consistently done later in the season and keeps that going through a full year, well, that will be the season he ends up with an MVP next to his name.
Pitching depth
Remember that glorious year of 2024 when the Mariners went through a 162-game season and had four pitchers in their starting rotation make at least 30 starts and another make 22?
The 2025 season was a stark reminder of the rarity of that happening. Ever.
The M’s had nine different pitchers make starts, including two Luis Castillos – the Rock and the Pebble. George Kirby started the season on the injured list, Bryce Miller and Logan Gilbert eventually found their way there and Bryan Woo would have his own stint on there, had his pectoral injury not come at the tail end of the regular season, and into the playoffs.
This season tested the starting pitching depth in the organization and the M’s learned that after Emerson Hancock and Logan Evans, there is not much ready to help contribute right away. They were fortunate to get 15 starts from Evans and 16 from Hancock that were often serviceable and were able to serve as bridge until the injured arms from the rotation were able to return.
“Injuries are going to happen, they’re part of the game, but I thought our guys did a really good job of coming back and getting back to the form that they were used to,” Wilson said.
One area where the Mariners were fortunate was health from their most important pieces in the bullpen. Matt Brash returned from Tommy John surgery and was terrific. Gabe Speier was one of the best lefty relievers in the league. And Andrés Muñoz set a career-high in saves, a career-low in ERA and relative to his production his contract (he has a $6 million club option in 2026) remains one of the biggest bargains in baseball.
Woooooooooooo
Following the 2023 season there were rumblings that Bryan Woo’s name was being brought up in trade talks.
Good thing those never came to fruition. He is now an ace.
Woo pitched like a No. 1 starter from March through September until suffering his pectoral injury. He threw at least six innings every start from the end of March until the end of August. He handled the load of a career-high in innings pitched. He flirted with a no-hitter in Yankee Stadium. He was a deserving All-Star selection.
And he might be the top of the M’s rotation going into 2026.
Dan Wilson is still a young manager
Wilson already earned one manager -of -the -year award from the Sporting News. He will get plenty of consideration from the BBWAA when their votes become public next month. And he should. Some of Wilson’s strongest qualities as a manager are his steadiness and letting his players lead and played a strong role in the M’s winning their first division title in 24 years.
But at times it was clear that Wilson was learning on the fly and it led to mistakes, whether it be the lineup decisions or the handling of the bullpen. It is an unfortunate reality that some of those mistakes showed up on the biggest stage of the postseason.
Wilson is still all of 208 games – regular season and playoffs – into his managerial career at any level. He should become more comfortable with decisions with more experience. At least, that is the hope.
“What’s in that clubhouse is determined and they’re not satisfied. And I think that speaks volumes,” Wilson said.