Lotte announced the signing of Tsuyoshi Yamazaki infielder to a developmental contract on April 14.

Yamazaki commented through the team, "I am truly grateful for being asked to join. I will play with all my heart and soul to help The Marines win and live up to expectations. I look forward to working with you."

Yamazaki joined Rakuten as the third pick in the 2017 draft. He played in 33 games in his first year with the team in 2018, and in 2023 he played in a career-high 117 games, batting .203 Home Run and 19 RBI. This season he did not play in regular season for the first or second varsity teams, and was released by Rakuten after the season ended.