In 2014, Kikau's first season of rugby league, he played 21 games for the Cowboys' Holden Cup team, scoring 11 tries. A centre in his rugby union days, Kikau switched to prop after joining the Cowboys.
2015
In 2015, Kikau played in a pre-season trial game with the Cowboys' first grade team. He scored a try in the sides 24–12 victory over the Townsville Blackhawks. On 2 May 2015, Kikau made his international debut for Fiji against Papua New Guinea in the Melanesian Cup match, playing off the interchange bench in the 22–10 win at Robina Stadium. On June 10, 2015, Kikau signed a two-year contract with the Penrith Panthers. On 14 September 2015, Kikau was named at prop in the 2015 NYC Team of the Year, finishing his Holden Cup career with the Cowboys with 32 tries from 42 matches.
2016
Kikau spent 2016 playing in the Panthers NSW Cup team. On 8 October 2016, Kikau played for Fiji against Samoa, starting at second-row in the 20–18 victory in Apia, Samoa.
Playing career
2017
In Round 2 of the 2017 NRL season, Kikau made his NRL debut for the Penrith Panthers against the Wests Tigers, playing off the interchange bench and scoring a try in the 36–2 win at Campbelltown Stadium. On 15 April 2017, Kikau re-signed his contract with the Penrith Panthers to the end of the 2019 season. On 6 May 2017, Kikau played for Fiji against Tonga, starting at second-row and scoring a try in the 26–24 loss at Campbelltown Stadium. Kikau would play most of the year playing in Penrith's NSW cup team where they won the NSW Intrust Super premiership against the Wyong Roos 20–12. A week later on 1 October 2017, Kikau played in the NRL State Championship match against QLD Cup winners the Papua New Guinea Hunters starting at second-row and scoring a try in the 42–18 boilover win. Kikau finished his debut year in the NRL with him playing in 9 matches and scoring 1 try for the Panthers in the 2017 NRL season. On 7 October 2017, Kikau was named in the 24-man squad for Fiji for the 2017 Rugby League World Cup. Kikau would have an outstanding tournament for Fiji playing in all of their 5 matches and scoring 3 tries and was rewarded with him being named in the World Cup Team of the Tournament.
2018
After his impressive World Cup campaign, Kikau would cement a permanent place in Penrith's top 17. Kikau made 25 appearances for Penrith in the 2018 NRL season as the club finished 5th at the end of the season and reached the elimination final against Cronulla-Sutherland before losing 21–20 at the Sydney Football Stadium.
2019
In round 23 of the 2019 NRL season, Kikau played his 50th NRL game for Penrith in their 24–10 defeat by the North Queensland Cowboys at 1300Smiles stadium. Kikau made a total of 18 appearances for Penrith in the 2019 NRL season as the club finished 10th on the table and missed out on the finals for the first time since 2015.