Watanabe spent two years at Niigata before moving on loan to Zweigen Kanazawa mid-way through the 2020 season.[2] After making 27 appearances for Zweigen Kanazawa in the second half of the season, his loan was extended for the whole of the 2021 season.
Watanabe scored his first professional goal in a 2-3 league defeat to Mito HollyHock in May 2021.[3]
Watanabe returned to Albirex Niigata for the 2022 season, although he only played a handful of games in the season they were promoted to the J1 League. He made his J1 League debut in March 2023, in a 2–2 draw with Hokkaido Consadole Sapporo and went on to make 27 appearances across all competitions in the 2023 season.
In December 2023, it was announced that Watanabe would be joining Yokohama F. Marinos.[4]
^"渡邊 泰基 選手 ツエーゲン金沢に期限付き移籍のお知らせ". アルビレックス新潟 公式サイト|ALBIREX NIIGATA OFFICIAL WEBSITE (in Japanese). Archived from the original on 14 February 2024. Retrieved 14 February 2024.
^"渡邊 泰基 選手 横浜F・マリノスに完全移籍のお知らせ". アルビレックス新潟 公式サイト|ALBIREX NIIGATA OFFICIAL WEBSITE (in Japanese). 27 December 2023. Archived from the original on 28 December 2023. Retrieved 14 February 2024.