The reason behind Roki Sasaki's decline in pitch velocity remains unclear; it is unlikely he will pitch in the second game.

After returning from the injured list and showing impressive relief performance, Los Angeles Dodgers' Japanese rookie pitcher Roki Sasaki faced five batters in the first game of the National League Championship Series. He issued two walks, gave up one hit, and allowed one run, with his pitch speed also dropping. Dodgers manager Dave Roberts stated that the cause is still undetermined and revealed that Sasaki is unlikely to pitch in the second game.

In his previous four postseason appearances, Sasaki’s four-seam fastball averaged over 99 mph, even exceeding 100 mph in the first two games. However, in yesterday’s game, his average velocity dropped to 98 mph, with none of his 13 pitches reaching triple digits; his fastest pitch was only 99.3 mph.

“We have noticed this issue but have yet to identify a definite cause,” Roberts said. “At this stage, it remains an unknown area for us as we gather more information. He has always been fully prepared to contribute to the team. It’s uncertain whether it’s fatigue or a mechanical issue; likely, it’s a combination of multiple factors, as is often the case.”

When asked if this meant Sasaki would miss the second game, Roberts responded, “I wouldn’t completely rule it out, but it’s indeed unlikely that he will be sent out to pitch.”

In the ninth inning of the first game, with two outs and runners on first and third, Sasaki was replaced. His successor, Blake Treinen, issued a walk to William Contreras and nearly hit Brice Turang with a pitch that could have tied the game, but ultimately managed to hold on for the win.

Despite Treinen’s poor form late in the season, Roberts continued to use him in critical moments, drawing some criticism from fans and media. Roberts explained, “I am well aware of his ability to pitch in high-pressure situations and believe he is currently managing his emotions well. Postseason performance in crucial innings is not about regular-season ERA; it’s about what he can deliver at those key moments. For me, trusting certain players in critical times is important, and Blake is definitely one of them.”