Will Klein’s – Will Klein went from Triple-A reliever to a World Series clutch arm for the Dodgers, and this season he’s quietly been effective again—just as the Mariners, missing key injured bullpen pieces, show signs of strain.
There’s a specific kind of baseball silence that falls over a bullpen when the ninth-inning plan runs out. By the time the World Series drifted into the bottom of the 18th, the Dodgers didn’t just hope— they got Will Klein to do what he’d been waiting for.
Klein was added to the active roster for the World Series. and after he didn’t get used in the first three rounds of the postseason. he was suddenly central in Game 3 against the Blue Jays. He pitched the final four innings of an 18-inning epic. struck out five. walked two. and allowed one hit without giving up a run. The Dodgers won on a walk-off in the bottom of the 18th, earning Klein the win.
Now the question isn’t just what Klein did in October. It’s why the Dodgers can summon him so effectively in 2026 at the exact moment the Mariners’ relief corps looks like it’s operating on borrowed time.
Right now, the Mariners bullpen ranks second in the majors with a 3.08 ERA despite the absence of Matt Brash, Gabe Speier, and Carlos Vargas, all injured. The numbers still suggest talent, but the margins show fatigue. Their WHIP ranks 18th, and they’re tied for 25th in batting average.
And that’s where Klein’s name keeps resurfacing. It’s not the legend version, either. It’s the version the M’s have already lived through once: last season in Triple-A Tacoma. Klein posted a 7.17 ERA and a 1.969 WHIP across 22 relief appearances before he was traded to the Dodgers. The trade sent Klein to Los Angeles in exchange for Joe Jacques.
The storyline for Los Angeles looks different because Klein—whenever he pitched for the Dodgers—was. After the trade. his Triple-A work with Oklahoma City was “nothing to write home about. ” but his MLB relief came with a different profile: a 2.35 ERA across 14 relief appearances. In the 2025 postseason. his World Series Game 3 performance became the kind of moment fans remember when they explain why a transaction mattered.
This season, the Dodgers aren’t overusing him, but they also aren’t hiding him. Klein has appeared in 13 games so far. In total. he’s pitched 18.1 innings for a 2.45 ERA. and he’s tied for 23rd among Major League relievers with a 0.5 fWAR. On the Mariners roster, that 0.5 fWAR would rank second behind Jose A. Ferrer at 0.7.
It’s tempting to blame the Mariners simply for losing someone who later produced in Los Angeles. But the trade wasn’t made with a World Series blueprint in mind. and it isn’t as if Klein was already arriving fully formed. Even within the argument about whether this is a “blip,” the details point to a specific kind of growth.
His fastball velocity has ranked in the top decile in all three of his Major League seasons. and through 2026 his barrel rate sits at 2.0 percent. The report also includes a caution that statistics can be framed to support different stories. and it will matter how Klein performs over the coming months.
Still, the Mariners have to operate in the present. They’re missing Brash, Speier, and Vargas. Their bullpen performance hasn’t collapsed—yet the WHIP rank of 18th and the tie for 25th in batting average suggest the margin for error is thin.
And for fans trying to reconcile regret with reality, there’s another piece of the trade that doesn’t help. The same swap that brought Klein to Los Angeles cost the Mariners Joe Jacques. In Tacoma. Jacques “did little during his short spell. ” and now he “seems determined to pitch himself out of affiliated ball” after a horrendous showing for the Mets in Triple-A Syracuse.
The result is an awkward. very human kind of trade legacy: one side sees an opportunity that finally clicked under a new usage plan. while the other side watches their bullpen carry on without the depth they thought they had. Klein’s been kept sparingly by the Dodgers. but when called upon. he’s been effective—again and again. in ways that make it hard to look away.
Will Klein Dodgers Mariners bullpen Matt Brash Gabe Speier Carlos Vargas Joe Jacques World Series Game 3 Blue Jays 2026 bullpen stats