| Team | Name JPN | Name ENG | Sources |
|---|---|---|---|
| Chunichi | 大野 雄大 | Ono, Yudai | Tokyo Sports 3/18/2017 |
| Yomiuri | マイコラス | Mikolas, Miles | Nikkan Sports 3/27/2017 |
| (road opener) | 菅野 智之 | Sugano, Tomoyuki | Nikkan Sports 3/27/2017 |
| Yokohama | 石田 健大 | Ishida, Kenta | Sponichi 1/9/2017 |
| (home opener) | 今永 昇太 | Imanaga, Shota | Nikkan Sports 3/18/2017 |
| Yakult | 石川 雅規 | Ishikawa, Masanori | Sponichi 3/17/2017 |
| Hanshin* | メッセンジャー | Messenger, Randy | Nikkan Sports 3/25/2017 |
| Hiroshima | ジョンソン | Johnson, Kris | Daily Sports 3/18/2017 |
| Seibu | 菊池 雄星 | Kikuchi, Yusei | Nikkan Sports 2/9/2017 |
| Nippon Ham | 有原 航平 | Arihara, Kohei | Sanspo 3/16/2017 |
| Rakuten | 美馬 学 | Mima, Manabu | Daily Sports 3/27/2017 |
| (home opener) | 則本 昂大 | Norimoto, Takahiro | Daily Sports 3/25/2017 |
| Orix | 金子 千尋 | Kaneko, Chihiro | Nikkan Sports 2/15/2017 |
| Lotte | 涌井 秀章 | Wakui, Hideaki | Sponichi 2/13/2017 |
| Softbank | 和田 毅 | Wada, Tsuyoshi | Nikkan Sports 2/23/2017 |
* Kanemoto formally told the media found out on March 24. He spoke to Messenger about the start on the last day of spring camp.