Grading the Seattle Mariners' performance in 0-3 series sweep vs. San Francisco Giants

The Seattle Mariners are stumbling out of the gate in a season where early momentum felt crucial. With just three wins in their first ten games, they’ve now fallen down to last place in the AL West.

While the front office’s approach has been clear — tread water early while evaluating the bullpen and cycling through options at third base and designated hitter — the results so far have done little to inspire confidence.

Instead of finding clarity, the Mariners seem to be uncovering more uncertainty. Roles remain in flux, the offense still lacks consistency, and the pitching staff is being pushed much harder than expected. It’s early, yes, but this team is looking more and more like an experiment.

Let’s break down their first road series of the year against the San Francisco Giants and see what it revealed — and what it didn’t.

Series Results

• Friday, April 4: SEA 9, SF 10
• Saturday, April 5: SEA 1, SF 4
• Sunday, April 6: SEA 4 , SF 5

Offense: C

The Mariners' offense delivered their familiar clunker in the second game of the series, failing to generate much of anything against Robbie Ray. But it’s worth noting that in Game 1, they put up nine runs in a wild, back-and-forth heartbreaker — a loss that was painful but undeniably entertaining. Once again, this team showed they’re capable of putting up crooked numbers when the game turns into a slugfest.

Julio Rodriguez has been a bright spot. Notably known for his slow starts, J-Rod has already racked up three home runs in this ten game stretch setting a personal best.

However, the underlying issue persists: situational hitting.

Despite the run total in the first game, the Mariners went just 3-for-16 with runners in scoring position — a stat line that left far too many opportunities on the table. That trend worsened the following nights as Seattle went 2-for-16 with RISP and stranded 19 runners, a performance that highlighted their ongoing struggles in clutch moments. The bats can come alive, but when it matters most, they’re still falling short.

Defense: C+

Ryan Bliss continues to flash his glove as a reliable plus defender, showing consistency in the field. Meanwhile, the corner outfielders have not been remotely as sharp. Victor Robles has shown steady improvement since the Detroit series but the smallest double clutch played a critical role in the Mariners Game 1 loss. One standout moment came in the second game of the series when Rodríguez fired a rocket to nail Willy Adames at second base as he tried to stretch a hustle double — a great sign of Rodríguez's growing defensive presence. 

Robles laid it all on the line in the final game of the series, making a spectacular catch in the bottom of the 9th. He launched himself over the wall in foul territory, leaving the field of play — and unfortunately, the game itself — with an injury sustained during the play. While that kind of effort is admirable, there are still concerns with this team’s outfield defense. Randy Arozarena, in particular, has looked disengaged at times, showing little urgency in the field and failing to deliver an accurate throw so far this season.

That said, while Seattle’s infield defense remains solid (when Jorge Polanco isn’t at third), there’s a clear distinction between being solid and being elite. And that difference was on full display in this series thanks to Matt Chapman and Willy Adames. Both put on a defensive clinic — combining smooth footwork, quick reactions, and powerful, on-target throws. These aren’t the kind of plays that rely on friendly hops or bailouts at first base. This is top-tier defensive baseball.

Adames, despite never having won a Gold Glove, has been a constant presence in the conversation, while Chapman, already the owner of two Platinum Gloves, remains the gold standard at third base. Their performances were not only impressive but pivotal — consistently flipping potential Mariners rallies into outs and helping keep the Giants in control of the series. If Seattle wants to tighten the margins in games like these, taking notes from the defensive intensity and precision of Adames and Chapman wouldn’t be a bad place to start.

Pitching: C

Luis F. Castillo, a 30-year-old righty, finally made his long-awaited first major league start — a milestone moment in a career that’s seen him grind through over a decade in the minors. His only previous taste of the big leagues came in 2022, when he tossed just 3.2 innings for the Detroit Tigers. On this night, Castillo didn’t deliver anything flashy, but he gave the Mariners exactly what they needed: three innings of serviceable work, allowing six hits, three earned runs, two walks, and picking up two strikeouts.

It was a tall order — not just for Castillo, but for the Mariners’ pitching staff overall. With the rotation in flux after Emerson Hancock’s rough outing against Detroit, the bullpen was already stretched thin. And on top of that, this was San Francisco’s home opener — a packed house and a 5–1 Giants team riding momentum. Despite all that, Castillo held his composure, kept the game within reach, and didn’t let the moment overwhelm him.

Unfortunately, the same couldn’t be said for Tayler Saucedo. Tasked with taking over in relief, Saucedo struggled mightily, allowing two runs while facing just three batters and recording only one out. His rough appearance earned him a quick hook — and a ticket back to Triple-A.

Jesse Hahn delivered one of the series’ feel-good moments. Pitching in the majors for the first time in four years, Hahn tossed over 30 pitches across two scoreless innings in the 7th and 8th in the second game of the series. It was a gutsy, composed outing — one the Mariners' offense unfortunately couldn’t reward, as they came up short once again.

Strategy: B

Through 10 games, Dan Wilson has shown he's no slouch in the manager’s seat. If anything, you almost have to feel for the guy. He’s checking the right boxes — the Mariners are playing aggressively on the bases, with even J.P. Crawford and Cal Raleigh getting in on the action with stolen bases of their own. Credit also goes to first base coach Eric Young Jr., who’s clearly doing his homework, putting runners in smart positions and consistently applying pressure on opposing pitchers.

Wilson’s also managing with a sharp eye on the matchups, leaning into analytics rather than intuition — a notable shift from Scott Servais’ style. While Servais certainly incorporated analytics, he often trusted his instincts and wasn’t shy about it. Sometimes that paid off, but more often than not, those gut calls led to costly missteps that played a role in his eventual exit. Wilson, to his credit, is taking a more calculated, data-driven approach.

Still, there’s only so much a manager can do. And what’s becoming more evident by the day is what fans and analysts alike feared all offseason: this Mariners roster might just be outclassed on a pure talent level. The better team won this series — that much was obvious on paper and even more so with the eye test. Wilson can make all the right moves, pull the right levers, and squeeze out wins with strategy, but he can’t singlehandedly will this team to the top of the division.

At some point, the front office will need to make a move — a shake-up, a call-up, or an impact acquisition — something to raise the ceiling of this roster. It’s unfair to ask Wilson to coach his way around a talent gap for 162 games if the Mariners intend to contend this season.

The Mariners will look to notch their first series win as they return home to the Pacific Northwest to face their heated rivals, the Houston Astros.