Yamaguchi hit .277 with 38 home runs and 81 RBI in 113 games for Lotte in 2026, slugging .602. That season-long power supports a middle-order role; adding on-base value to a .329 OBP while preserving his extra-base threat is the next appealing challenge.
Updated 2026-11-10Yamaguchi attended Meio High School and was selected by Lotte in the fourth round in 2018, with his first top-level record arriving in 2021. He hit nine homers in 78 games that year, then exceeded one hundred appearances and reached sixteen homers in 2022, developing into a right-handed power option.
He received 474 plate appearances in 2023, contributing fourteen homers and 57 RBI, before his first-team game totals fell to 51 and then 35 over the next two seasons. His early professional career was not a continuous rise. The power remained part of his game, while changes in opportunities repeatedly required him to compete for a place again.
Five straight first-inning hits and an eight-pitcher relay carried Japan past Hiroshima 5–1. Hiroto Takahashi worked two scoreless innings, while Koki Yamaguchi drove in the opening run.
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