In July 2019, Nanai represented the Northern Marlins at the QRL Under-16 Junior State Championships.[8] On 18 September 2019, he started at second-row in Kirwan State High School's NRL Schoolboy Cup win over Westfields Sports High School.[9] On 29 September 2019, he represented Queensland Country under-16, scoring a hat trick and being named Man of the Match in their 44–4 win over Queensland City under-16.[10]
In January 2020, Nanai was selected in the Queensland Under-18 Emerging Origin squad.[11] In September 2020, Nanai played for Kirwan in their Queensland state final win over Palm Beach Currumbin State High School, scoring two tries.[12]
On 7 October 2020, Nanai joined North Queensland's NRL squad on a development contract for the 2021 season.[13]
In April, Nanai signed a one-year contract extension to remain at North Queensland until the end of 2023.[18]
In round 7, Nanai was sent to the sin bin and later scored a try during North Queensland's 30–4 victory over the Gold Coast.[19]
In round 11, Nanai scored two tries for North Queensland in their shock 36–6 upset victory over Melbourne.[20]
On 30 May, Nanai was selected to debut for the Queensland State of Origin team for game one of the 2022 State of Origin series. Nanai was taken from the field during Queensland's 16–10 victory with an ankle injury.[21]
In round 20, Nanai scored two tries for North Queensland in a 34–8 victory over St. George Illawarra.[22]
Nanai finished a great year receiving the Dally M Rookie of the Year award and the Dally M Second Rower of the year and finishing the season with 17 tries from 23 matches.[23]
In round 2 of the 2023 NRL season, Nanai scored two tries for North Queensland in their 28-16 loss against arch-rivals Brisbane.[25]
In round 4 against the Gold Coast, Nanai was sent to the sin bin and later suspended for two matches after a dangerous throw on Phillip Sami. Nanai played two games for Queensland in the 2023 State of Origin series which Queensland won 2-1.[26]
On 25 July, it was announced that Nanai would miss at least four matches after he suffered a high grade AC joint injury during North Queensland's victory over Parramatta.[27][28]
Nanai played 13 games for North Queensland in the 2023 NRL season and scored six tries as the club finished 11th on the table.[29]
2024
In round 9 of the 2024 NRL season, Nanai scored two tries in North Queensland's 28-26 loss against the Dolphins.[30]
In round 12, Nanai scored two tries for North Queensland in their 42-28 victory over strugglers the Wests Tigers.[31]
Nanai was named in the second row for Queensland ahead of game one in the 2024 State of Origin series.[32]
Nanai played 23 games for North Queensland in the 2024 NRL season as they finished 5th on the table. He played in both finals games for North Queensland as they were eliminated in the second week by Cronulla.[33]
