On the 7th, Lotte announced that they had notified pitcher Fuki Tanaka that they would not be signing a contract for next season. They also announced that the development contracts of pitchers Humiya Motomae pitcher, Ryotaro Mori pitcher Ryota Nakamura pitcher, Seiun Akiyama pitcher and Rui Katsumata had expired.

Fuki Tanaka joined the Lotte Marines as the first pick in the 2021 development draft. In his fourth year this season, he pitched in 18 games with a record of 1 win and 2 losses and ERA of 3.63, but in July and August he pitched in five games with a 0.00 ERA, bringing ERA to 1.86 up until September 24th. However, in his final appearance of the season against Seibu on September 25th, he pitched 5 2/3 innings and gave up 9 runs, causing ERA to jump significantly.