It’s Roki Sasaki season.
Since news broke that the 23-year-old Japanese phenom is jumping stateside this winter, Sasaki has captured headlines and imaginations across the baseball world. A potential ace available for a relative pittance, the long-limbed hurler is firmly on the radar and within the budgets of all 30 teams.
Only time will unravel the mysteries of Sasaki’s incredibly complex free agency, so let’s spend some time investigating him as a player.
What type of pitcher is he, exactly? What pitches does Sasaki throw? How hard are they? Are there injury or durability concerns? Who are some loose comparisons already in MLB? What are reasonable expectations?
Let’s dive into the data and build a big-picture scouting report on this offseason’s most sought-after arm.
Sasaki’s first tastes of pro baseball
Sasaki has been a known commodity since his amateur days when he threw a fastball 101 mph, breaking Shohei Ohtani’s record for the hardest fastball ever thrown by a Japanese high schooler. Despite drawing interest from MLB teams right out of high school, Sasaki opted to play in NPB for the Chiba Lotte Marines who drafted him first overall in 2019.
The highly touted hurler sat out the 2020 season to rest his young arm, at his team’s behest. In 2021, he broke out as one of the best pitchers in Japan’s top league. The next season, Sasaki solidified himself as a game-changing force, tossing a perfect game and, at one point, retiring 52 consecutive batters. Then, he turned 21 years old. He pitched twice for Japan in the World Baseball Classic, starting the team’s semifinal game against Mexico in which he dominated for 3 2/3 innings before a few soft knocks and a three-run blast sullied his line.
Back in NPB, Sasaki continued his excellence in 2023 and 2024, but struggled to stay healthy, hucking 202 innings combined across the two seasons.
Sasaki’s 2024
Though Sasaki logged 111 innings this past season and pitched to a 2.35 ERA, his stuff was unavoidably down. Most notably, his fastball clocked in at 1.9 mph slower on average compared to 2023. He also missed a batch of starts with an unspecified arm issue, an ailment that almost certainly played a role in his diminished velocity. But Sasaki was nails when it mattered, tossing eight shutout frames in his last outing of the year, a masterful nine-strikeout showing in the playoffs.
Durability and injury concerns
If Sasaki was a “normal”…