The dust has settled. It feels like just yesterday George Springer’s three-run homer landed in the left field seats of the Rogers Centre to deliver a stunning blow to the Mariners just eight outs away from the franchise’s first World Series appearance.
For the Mariners fanbase, it’d be easy to despair after coming up just short with no guarantee of return. After all, you never know what’ll happen from here on out. With pitchers all over the league suffering unprecedented numbers of elbow injuries and a potential labor dispute looming when the collective bargaining agreement expires following the 2026 season, there’s plenty of factors that could derail the Mariners’ recent rise to new heights.
Improvement hasn’t always be linear. In 2022, everyone thought the M’s were close to changing the guard and claiming AL West supremacy from the Astros. Instead, they missed the postseason the following two years before finally ending their division championship drought in 2025. The margin for error in baseball is small, especially as a mid-level payroll team in a league without a salary cap.
I’m not here to doom, however—anything could happen, but the Mariners are better positioned to win now than they ever have been. The ingredients are present to return to the postseason in 2026 and make another run at the first pennant in franchise history. The Mariners should be among the American League’s elite if things break right.
Additions and losses
Gone is postseason hero Jorge Polanco, who delivered multiple timely home runs off of Tarik Skubal and an extra-inning, walk-off single to send the Mariners to their first ALCS in 24 years. For better or worse, the M’s were unable or unwilling to match the one-year, $20 million price tag offered by the Mets that sends Polanco to Queens for the 2026 season.
On the other hand, the Mariners were quick to make the move to lock down first baseman Josh Naylor, whose pest-like baserunning and consistent bat were instrumental following his trade deadline acquisition and provide some stability at the corner-infield position. A $92.5 million deal will keep Naylor in the fold for the next four years unless the veteran chooses to waive his no-trade clause.
The Mariners also added outfielder Rob Refsnyder, who looks to fall into a role similar to that previously held by Dylan Moore—a versatile fielder who purports to mash lefties. This isn’t to say Refsnyder possesses the super-utility qualities of Moore—he doesn’t, though you could still stick him in a couple places to help rotate players in and out of the lineup. Rather, the M’s lineup was so parched for a righty platoon bat that it took Moore several months of hardly reaching base at all to finally be designated for assignment. (This is the harsh truth. Please forgive me, Dylan, as I’ll always love you and appreciate your contributions.) If the Mariners are facing a lefty starter, you can expect Refsnyder to be in the lineup one way or another.
Oh, and who can forget the M’s traded one of their top prospects in Harry Ford? In return, they received lefty reliever José Ferrer from the Washington Nationals, addressing a need for an additional southpaw in the bullpen. Late in the regular season and into the postseason in 2025, mileage racked up on the arm of Gabe Speier, then the Mariners’ only lefty out of the bullpen. This became a breeze for opposing managers to strategize against. Ferrer, who is unproven at the major league level, shows promise in his peripherals, with elite ground-ball and walk rates. He has an outstanding opportunity to take a step forward for a contending team.
Over the following weeks, the offseason went pretty quiet. Though top prospect Colt Emerson could contribute, and Cole Young should continue to stack big-league reps at second base, it may not have been ideal to rely on them heavily as everyday starters to begin 2026. However, with many infield options having come off the board, including our fan-favorite Eugenio Suárez signing with the Reds, the possibility of rolling with the young guns seemed to be increasing every day—that is, until this last Monday.
Finding the missing piece
Over the last couple of years, journalists and fans alike have mocked many trades between the Mariners and Cardinals. The M’s have been progressing further into consistent playoff contention, but the Cardinals have fallen into a rebuild, creating a classic buyer-seller dynamic between the two teams. Not only this, but the Mariners’ consistent pitching development has made some of their prospects the perfect trade chips to dangle in front a Cardinals team that has lacked pitching but holds an assortment of major league bats they could potentially flip to bolster their farm system.
A trade between Seattle and St. Louis has felt inevitable for a while. It finally happened.
In a three-team trade Monday, the Mariners acquired infielder/outfielder Brendan Donovan from the Cardinals for right-handed pitcher Jurrangelo Cijntje, outfielder Tai Peete, and a 2026 Competitive Balance Round B draft pick. The M’s also sent infielder Ben Williamson to the Tampa Bay Rays in the deal.
On paper, Donovan is a perfect fit for the Mariners roster. As an infielder with the ability to play at both second and third, Donovan’s presence could allow youngsters Young and Emerson to be consistently rotated into the lineup while not bearing the same level of pressure to produce. The pickup also gives the Mariners a true lead-off hitter, something they have lacked for much of the last couple of years.
An All-Star for the first time in 2025, Donovan has been seen as one of the anchoring pieces of the Cardinals’ rebuild. He comes with two years of club control before becoming a free agent after the 2027 season. Though he will be arbitration-eligible one more time next season, he will carry a payroll hit of only $5.8 million this year, an incredible value for one of the most consistent bats in the majors over his four years in St. Louis.
The addition of Donovan creates arguably the deepest Mariners lineup to begin a season in a couple of decades. With Donovan in the leadoff spot, the top of the order is chock-full of power threats, and outfielder Randy Arozarena’s somewhat streaky production can be relegated to a more appropriate role in the middle of the lineup.
While the bottom of the lineup isn’t quite as flashy, there’s plenty of room for upside from developing players Young, Emerson and outfielder Dominic Canzone. Outfielder Luke Raley, who has a decent track record in the majors against righties, and outfielder Víctor Robles could both bounce back with healthier 2025 seasons. The bottom of the lineup will also feature the always-steady table-setter, shortstop J.P. Crawford.
Pair this with a deep starting pitching rotation that hopes for a healthier season and a bullpen that finally picked up another lefty, the Mariners have a reasonable argument to be considered the American League favorites in 2026.
Message in a Bottle
@hacesolmccue asked: How do we know that Donovan won’t fall off a cliff like [Jesse] Winker did?
The short answer is, we don’t. Future production is never guaranteed in this game, and the past simply makes up the data points used to make informed decisions. Donovan could drop off the second he arrives in Seattle, much like Winker. It’s always a possibility, especially when we consider human nature and the reality that this is a person picking up their life and moving it halfway across the country to somewhere unfamiliar. It also doesn’t help that T-Mobile Park is the least hitter-friendly ballpark by a pretty fair margin, with a Statcast Park Factor of 91.
As for Donovan’s particular circumstances, though, I’d say it’s less likely his production tanks the way that Winker’s did. I’d argue there were more warning signs in Winker’s case.
Unlike Winker, Donovan isn’t coming from one of the most hitter-friendly ballparks in the majors in Cincinnati. With a Park Factor of 100, Busch Stadium in St. Louis represents the average offensive environment in the majors. In terms of extremes, Winker may as well have moved from the Sahara Desert to the North Pole. Donovan’s move would be more akin to moving from a temperate climate (like Seattle, maybe!) to the North Pole.
It also didn’t help Winker that his production was largely fueled by extra base hits. Using the statistic Isolated Power (ISO, calculated by subtracting batting average from slugging percentage), we can see how much of a player’s slugging percentage comes from extra base hits. From 2017 to 2021 in Cincinnati, Winker put up a well-above-average .216 ISO. Donovan is much more of a threat to simply reach base with singles, with a career ISO of .129. Hypothetically, this should play much better with T-Mobile Park’s rather small outfield, which can suppress extra base hits heavily.
Most importantly, Donovan’s numbers have been extremely consistent through four years in the majors, and especially the last three seasons if you exclude his most-productive, rookie season when pitchers were still adjusting to him. Winker’s numbers, while more impressive at times, were always more volatile. I could talk about this more in-depth, but I think the numbers speak for themselves. There hasn’t been much variance from Donovan year-to-year.
Donovan’s production at the plate over four years in the majors has been extremely consistent. (Source: Fangraphs.com)
Lastly, I think the context of the trade matters as well. The alternative at third base, at least to start the year, likely would’ve been Williamson, who put up a 76 wRC+ in 2025. Now, I don’t say this to disparage Williamson—a lot of his value comes from his defense—but Donovan’s production at the plate would have to take a serious hit to not be a significant improvement. Overall, Donovan is a very good bet to make this lineup better, which should be the front office’s priority as a clear division favorite in the middle of a competitive window.
This is Rolling Roof Rundown, a newsletter covering the Seattle Mariners. You can follow James @rollingroofrundown.com on Bluesky for more takes and updates, and if you haven’t already, subscribe to the newsletter to have it delivered straight to your inbox. Rolling Roof Rundown can be found Instagram as well.