27-year-old left-hander Shinnosuke Ogasawara will make his Major League Baseball debut as the starter for the Washington Nationals in Sunday afternoon's contest against the Boston Red Sox, Mark Zuckerman reported on social media Saturday evening.
It's an historic moment for the Nationals as a ballclub, as Ogasawara is the team's first signing directly out of Japan's top professional league, Nippon Professional Baseball (though he will be the team's second Japanese player; Tomo Ohka pitched in half the team's inaugural season in Washington after spending three and a half years with the Expos). Ogasawara came and went between NPB's Chunichi Dragons and their minor league affiliate, but in nine seasons he appeared in 161 games for the Dragons, throwing just under a thousand innings to a 3.62 ERA, and was selected to the league's 2023 All-Star Game.
Ogasawara prioritizes finesse and soft contact over strikeout heat and extreme movement; he's topped out at just 90 MPH on his four-seam fastball in the minor leagues this year. Prospect Savant, a helpful tool for visualizing Statcast data for Triple-A play, shows Ogasawara as throwing six distinct pitches; he threw five of them in a spring outing against the Marlins where he went two innings. That's a little bit of a concerning profile for the Nationals, who have one of the most frustrating up-the-middle defenses in Keibert Ruiz, CJ Abrams, and Luis García Jr., and could struggle with handling a large number of ground balls. Of course, the point is moot if Ogasawara can't generate weak contact, which will be the ultimate major key in whether or not he's able to stick in the majors.
Shinnosuke, nicknamed "Big Cowboy," made his regular season stateside debut against the Phillies' Triple-A affiliate Lehigh Valley IronPigs on April 1, going six strong innings, allowing just one run on five hits and no walks and striking out six. Because series in the minor leagues are six games long, the IronPigs saw Ogasawara again five days later, prompting a seven-run implosion over four innings. He was more effective against the Yankees' affiliate RailRiders, though he walked four over five innings, but was placed on the 7-day injured list 3 days later with an oblique strain. A rehab assignment began on June 14, with Ogasawara completing two scoreless innings against the Marlins' Florida Complex League squad, and he's since made two more starts at High-A Wilmington, striking out 10 over 7 innings and allowing 4 runs. On a rate basis, among players 28 and under, Ogasawara has one of the better expected wOBAs against him in Triple-A this year, but only throwing 15 innings at the level makes that difficult to measure.
Nationals fans are, understandably, frustrated about the lack of a call-up for former top prospect Cade Cavalli, who was optioned to Triple-A Rochester upon the completion of his rehab assignment following Tommy John surgery in 2023. The Nationals, for their part, seem to be sticking to their guns; the team entered 2025 with the message that they planned to build Cavalli up to a major league workload before he returned to the big league roster in the second half of the season, and that's appeared to be the case so far. Cavalli has made 12 starts across three levels of the minors this year but has only thrown 50 innings total. The big league club currently is prioritizing simply getting innings out of their pitchers, especially with the recent ineffectiveness of much of the starting rotation. Cavalli should most likely still find a return to the bigs in August or September, regardless of performance.
The move also comes after Mason Thompson was activated from the injured list on Saturday. Thompson last pitched in the majors in 2023, undergoing Tommy John surgery at the start of last year. The Nationals optioned Zach Brzykcy to Triple-A in a corresponding move, and transferred Derek Law to the 60-day injured list to make room on the secondary 40-man roster. Law is headed for an MRI after experiencing recurring elbow pain in his most recent rehab appearance; the transfer to the 60-day list does not affect his eligibility to return, however, as he has spent longer than that on the IL.
For more coverage on Ogasawara, you can find the piece I wrote about him when the team signed him in January HERE. Those curious can also find his YouTube channel, where he posts vlogs during the offseason, HERE.