Tonumaipea was named in Melbourne's 2017 Auckland Nines squad and he was captained for the Storm with Kenny Bromwich. On 5 February at 2017 Auckland Nines against the Newcastle Knights, he scored a try in the 20-10 win, a try in Melbourne's 25-12 win at the quarter finals against the North Queensland Cowboys and a try in Melbourne's 16-21 loss over the Sydney Roosters at the semi-final at Eden Park. He played 5 matches and scored 3 tries for the Nines and in the NRL, he played 7 matches and 2 tries. On 6 October, Tonumaipea was selected the Samoa 24-men squad for the 2017 Rugby League World Cup campaign. On 11 November in the 2017 Rugby League World Cup against Scotland national rugby league team, Tonumaipea scored his first international try for Samoa in the 14 all draw at Barlow Park in Cairns and he played at fullback, but Samoa progressing on for-and-against average finals series. He played 4 matches and 1 try in the World Cup tournament.