Roki Sasaki's rookie season might just go down as one of the strangest in Los Angeles Dodgers history.

The highest-profile international amateur free agent since Shohei Ohtani, who took part in an extensive and expansive free agency process before ultimately choosing the Dodgers as his new MLB home, Sasaki didn't exactly take the league by storm right out of the gate, struggling to command his stuff over multiple innings of action at a time before having his season sidelined with a shoulder injury.

Initially, it looked like Sasaki's season was over, with Dave Roberts going so far as to suggest he wasn't willing to put a timeline on the 23-year-old's return, but through it all, fate intervened. LA figured out a way to get Sasaki's shoulder back on track; his rehab was successful, and he returned to the mound in Oklahoma City in August, first as a starting pitcher and then as a relief option out of the bullpen. Sasaki had to work through shoulder setbacks, having to make an extra AAA appearance before returning to Los Angeles, but in the end, he pitched two scoreless innings at the end of September to all but secure a spot on the postseason roster.

From there, Sasaki's role grew with each passing appearance, with skipper Dave Roberts feeling more and more confident in his now-rookie reliever with each passing appearance. Sasaki retired three in order to close out the Wild Card Round, got out four over two games in Philadelphia on the way to his first two professional saves – bailing out Blake Treinin for a rough go in Game 2 – and ultimately kept his ERA perfect in Game 4 of the NLDS, earning two strikeouts over three innings to retire all of the Phillies' best hitters on way or another.

With the NLCS now locked up, with a showdown against either the Chicago Cubs or the Milwaukee Brewers forthcoming depending on which team pulls out the dub in Game 5, the Dodgers have some time to rest up, re-tool their roster ever so slightly, and return to the field, be that Dodger Stadium, Wrigley Field, or American Family Field, with an even better play for a World Series surge.

One thing that can't change, however, is using Sasaki as the team's closer, as no matter which team they end up facing off against in the NLCS, there isn't a relief pitcher Roberts should have more confidence in than the rookie from Rikuzentakata, Iwate, Japan.

Los Angeles Dodgers pitcher Roki Sasaki (11) reacts after the tenth inning against the Philadelphia Phillies during game four of the NLDS round for the 2025 MLB playoffs at Dodger Stadium.
Mandatory Credit: Jayne Kamin-Oncea-Imagn Images

Roki Sasaki could make or break the NLCS for the Dodgers

Through six games of action, Sasaki has been perfect.

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Okay, technically, he's allowed two hits over 7.1 innings of action, one in the regular season against the Seattle Mariners and another in the postseason against the Phillies, but in the end, neither resulted in a run. Even when Sasaki puts the ball where an opposing hitter could theoretically get to it, he's avoided making any major mistakes thus far, allowing mostly pop-ups that have been fielded by the likes of Max Muncy and Teoscar Hernandez.

With a fastball routinely clocking in at over 100 and a borderline unhittable splitter, Sasaki has retired some of the best hitters in baseball, including both the AL and NL home run leaders, Cal Raleigh and Kyle Schwarber, and has lived up to the moment in a major way, being so locked in during Game 5 that he didn't even take off this glove during the bottom of the ninth inning just in case he was needed at the top of the 10th.

If that doesn't speak to his prowess as a closer, what does?

Now granted, if the Dodgers end up facing off against the Cubs, who are surging against the top seed, Sasaki will almost certainly have to face off against some of the better home run hitters in baseball, with Michael Busch, Seiya Suzuki, and Pete Crow-Armstrong all finishing out the regular season with at least 30 home runs. While the Brewers weren't as home run happy in their quest for NL supremacy, they still have Christian Yelich, who had 29, and Jackson Chourio, who has been on a postseason roll after recording just 21 in the regular season. But does that really matter?

While Sasaki hasn't faced the Brewers yet in his MLB career, he has actually faced off against the Cubs twice, first in his MLB pitching debut and again a few weeks later at home. Was Sasaki particularly good in either game? No, as he earned his first and to this point only loss in one of the games and only lasted three innings in the others – earning a combined ERA of 2.25 with five hits, two earned runs, and seven walks versus six strikeouts, but then again, is either game even relevant? Sasaki is coming out of the bullpen now, and as a result, everything has changed.

Now granted, what is relevant is that Sasaki has been a victim of his own success, with the rookie reliever only allowing two hits so far during his stint out of the bullpen between the regular season and the playoffs. Roberts, the Dodgers, and their fans don't know how Sasaki will respond when he gives up multiple hits in a game, or even watches a ball fly into the outfield because he put it in the wrong spot. Will he crumble? Or will he brush off the adversity, request a new ball, and go back to work like any good reliever has to?

Through you-know-what or high water, Sasaki has to be the guy for the Dodgers in the NLCS and beyond until proven otherwise. Tanner Scott is ineligible for the rest of the postseason, Blake Treinin is a walking blown save, and the rest of the Dodgers' bullpen is better suited for situational baseball than a Kenley Jansen duty. While that fact may ultimately cost Los Angeles in the end if he can't handle the adversity of a tough outing, in the end, this is the roster Andrew Friedman put together, and because he effectively whiffed on the position in free agency and at the trade deadline, the Dodgers' best ninth inning option is a 23-year-old rookie who spent half the season on IL with no real closing experience. Fortunately, Sasaki has played up to the moment every time he's been called upon, so who knows, maybe this is just crazy enough to bring another World Series banner to Dodger Stadium?