LOS ANGELES — The shoulder injury that recently landed Los Angeles Dodgers right-hander Roki Sasaki on the injured list is a lesser version of something he experienced in Japan last season, he said. Whether it’s the primary reason for a mysterious drop in velocity is still, in his mind, unclear.

“It’s hard to tell if it’s the main reason why my velo and command was affected,” Sasaki said through an interpreter on Wednesday.

Sasaki described his injury — listed by the team as an impingement — as “not necessarily pain, but it just wasn’t the ideal way that I want my shoulder to move.” The discomfort began two starts ago, around the beginning of May. Sasaki proceeded to allow a combined eight runs on 11 hits and four walks in nine innings before the Dodgers placed him on the IL, where he joined Blake Snell and Tyler Glasnow, both of whom are also dealing with shoulder woes.

Sasaki, the highly sought-after pitching phenom who blew up the international market last offseason, has posted a 4.72 ERA in his first eight starts in the big leagues, accumulating almost as many walks (22) as strikeouts (24) in 34⅓ innings.

The struggles have in many ways validated thoughts from people within the Dodgers and throughout the industry that Sasaki, 23, is far from a finished product, despite his outsize talent. But the performance of Sasaki’s four-seam fastball, a crucial pitch to set up his wipeout splitter, has been alarming.

Sasaki’s fastball routinely reached triple digits in Japan, but he hasn’t hit that mark since his season-opening start from Tokyo in mid-March. Since then, Sasaki’s fastball has averaged 95.7 mph. In three of his starts, including his two most recent, it has dropped into the 94 mph range. All told, opposing hitters have posted an .873 OPS against that pitch.

Fastball command was a primary concern to evaluators who watched Sasaki in 2024, but he nonetheless managed to post a 2.35 ERA and strike out 129 batters while limited to 111 innings. Dodgers manager Dave Roberts said he believes Sasaki’s current velocity drop is a product of mechanical adjustments he’s still working through but one that also has been exacerbated by another bout with shoulder woes.

Asked what has contributed to the discomfort these past two years, Sasaki said: “There’s nothing, per se, that I can say is for certain. But it is a very good time for me to make sure that I can get to the bottom of it.”

Sasaki is not currently throwing, but Roberts said he is not expected to receive a pain-relieving injection. The Dodgers will stage a bullpen game on Thursday in what was supposed to be Sasaki’s next scheduled start. They also will welcome Clayton Kershaw back to their rotation on Saturday, giving them a fifth starter.

Snell and Glasnow have both been cleared by doctors to restart their throwing programs, but they must clear several steps before a return path can be carved out.

The same can be said for Sasaki, who will essentially start from scratch, which is an opportunity to also work on some of the mechanical adjustments required for him to succeed in the major leagues.

“I do think that this is a good time to be able to do that,” Sasaki said. “I want to make sure that I’m fully healthy and be able to address anything that I had so that it leads to better performance.”