How Dodgers’ Yoshinobu Yamamoto’s ERA doubled in just one start

The Los Angeles Dodgers were confident heading into Thursday’s game against the Arizona Diamondbacks. Their ace, Yoshinobu Yamamoto, was on the mound, ready to shut the Diamondbacks’ offense down in the opening game of their four-game series. After two swings from Gabriel Moreno and Ketel Marte, the Dodgers’ ace and National League Cy Young candidate saw his ERA double from 0.90 to 1.80.

Yamamoto is one of Major League Baseball’s best pitchers in 2025 and had a minuscule ERA before Thursday’s game. He cruised through the first three innings, but found himself with the bases loaded in the fourth. Moreno stepped in and one grand slam later, the Dodgers were behind 4-0. Marte tagged him for a solo shot one inning later, sealing the win for Arizona.

In all of his starts this season, the series opener in Arizona was Yamamoto’s worst start of the year by far. Prior to that, he played exceptionally well, far better than his record would suggest. He is 4-3 on the season, but his first two losses are largely thanks to a lack of run support. His offense left him hanging again on Thursday. Shohei Ohtani hit a home-run in the ninth to bring Los Angeles within two runs, but it wasn’t enough.

Despite a rough night, Yamamoto’s ERA is still within the top ten in MLB. Dodgers manager Dave Roberts acknowledged his ace’s performance was an anomaly from his normal dominance.

“I think the story is he just wasn’t completely sharp tonight,” said Roberts.

Yamamoto is under a lot of pressure to serve as the ace and sustain his team’s starting rotation. Los Angeles has a few of their starters, including Ohtani, working their way back to the mound. Once they return, Yamamoto won’t have to do as much every time he takes the mound.

It was unlikely that he would be able to keep his ERA under 1.00 for much longer, but Yamamoto is still a name to be feared by opposing batters throughout the league.