Manly Warringah Sea Eagles Waerea-Hargreaves was signed by the
Manly-Warringah Sea Eagles recruitment manager,
Noel Cleal, despite never having played rugby league. Waerea-Hargreaves played in the Sea Eagles
NYC team in 2008 and 2009. Waerea-Hargreaves made his
NRL debut against the
Brisbane Broncos in round 9, playing off the interchange bench in the Sea Eagles 22–20 win at
Suncorp Stadium. In his next match, in round 15, Waerea-Hargreaves scored his first NRL career try in the Sea Eagles 20–14 victory over the
Canberra Raiders at
Brookvale Oval. Waerea-Hargreaves played 6 matches and scored a try during the
season. He was also named in the
Toyota Cup team of the year.
Sydney Roosters 2010 Waerea-Hargreaves joined the
Sydney Roosters in 2010 on a three-year deal. In week 1 of the finals, against
Wests Tigers, Waerea-Hargreaves was on a receiving end of big hit from
Simon Dwyer. The Roosters won 19–15 in golden point extra time due to a
Shaun Kenny-Dowall 70-metre intercept try. Waerea-Hargreaves played off the interchange bench in the
2010 NRL Grand Final, losing 32–8 to the
St George-Illawarra Dragons. He played in 19 matches for the Roosters in
2010.
2011 In round 25, against the
Cronulla-Sutherland Sharks, Waerea-Hargreaves scored his first club try for the Roosters in the 36–25 win at the
SFS. He played in 21 matches and scored a try for the
season.
2012 On 6 February, Waerea-Hargreaves played for the
NRL All Stars on the interchange bench in the 28–12 win over the
Indigenous All Stars. He played in 23 matches and scored 3 tries in
2012.
2013 In round 9, he copped a 5-week suspension after being sent off for a head tackle against the Sea Eagles. Waerea-Hargreaves played prop in his second
grand final against the Sea Eagles, the Roosters winning 26–18. Waerea-Hargreaves played in 21 matches and scored a try in the Roosters' successful
season.
2014 In round 11, against the
Canterbury-Bankstown Bulldogs at
ANZ Stadium, Waerea-Hargreaves played his 100th NRL career match in the Roosters 32–12 win. In round 19, against the
Penrith Panthers at the SFS, he played his 100th match for the Roosters in the 32–12 win. Waerea-Hargreaves finished off the
2014 season with him playing in 26 matches and scoring a try. In December, the
Canberra Raiders offered Waerea-Hargreaves a multimillion-dollar contract but ended negotiations after he failed to meet a deadline.
2015 On 24 January, Waerea-Hargreaves was the co-captain of Roosters
2015 Auckland Nines squad alongside
Mitchell Pearce. On 13 February, he played for the
NRL All Stars in the
2015 All Stars match. The NRL All Stars lost 20–6 to the
Indigenous All Stars. In round 23, against the
Parramatta Eels, Waerea-Hargreaves scored one of the best solo tries of the season, scoring a crucial try by steamrolling two defenders and brushed off two more to score next to the posts in the Roosters 28–18 win. In the next match against the
Brisbane Broncos, his season ended after he suffered a knee injury. Waerea-Hargreaves finished the
year with him playing in 19 matches and scoring 2 tries.
2016 In round 9, against the
Newcastle Knights, Waerea-Hargreaves made his return for the Roosters from injury, playing off the interchange bench in the 38–0 win at the Sydney Football Stadium. Waerea-Hargreaves finished the
2016 NRL season with him playing in 14 matches for the Roosters.
2017 Waerea-Hargreaves played in every game of the
2017 NRL season for the Roosters as the club fell one game short of a grand final appearance suffering a shock defeat by North Queensland in the preliminary final 29–16.
2018 Waerea-Hargreaves was part of the Easts side which won their 4th minor premiership in 6 seasons. On 30 September, Waerea-Hargreaves played in Eastern Suburbs 21–6 victory over Melbourne in the
2018 NRL grand final winning his second premiership as a player.
2019 In round 17 against North Queensland, Waerea-Hargreaves was placed on report in the club's 15–12 loss at the
Central Coast Stadium after allegedly headbutting North Queensland player
Josh McGuire. Waerea-Hargreaves was later cleared of any wrongdoing but was initially facing a two match ban. In round 25 against arch rivals
South Sydney, Waerea-Hargreaves was placed on report after hitting Souths player
Liam Knight with a late tackle around the head which left Knight bleeding on the ground. The Roosters would go on to lose the match 16–10 at
ANZ Stadium. In the qualifying final against South Sydney, Waerea-Hargreaves was placed on report and later suspended for one match after being found guilty of tripping Souths player
James Roberts. Waerea-Hargreaves missed the club's preliminary final victory over Melbourne but played in the
2019 NRL Grand Final where the
Sydney Roosters won the match 14–8 against the
Canberra Raiders at
ANZ Stadium. It was the club's second consecutive premiership and the third premiership for Waerea-Hargreaves as a player. On 22 November 2019, it was announced that Waerea-Hargreaves had signed a three-year contract extension to keep him at the club until the end of the 2023 season.
2020 Waerea-Hargreaves played 18 games for the club in the
2020 NRL season. They fell short of a third successive premiership losing to Canberra in the elimination final.
2021 Waerea-Hargreaves played a total of 23 games for the Sydney Roosters in the
2021 NRL season including the club's two finals matches. The Sydney Roosters would be eliminated from the second week of the finals losing to Manly 42-6.
2022 In round 24 of the
2022 NRL season, Waerea-Hargreaves was sent to the sin bin for a dangerous high tackle during the Sydney Roosters upset victory over
Melbourne. In the elimination final, Waerea-Hargreaves was sent to the sin bin for a dangerous tackle in the club's upset defeat to arch-rivals South Sydney which ended their season. In the third group stage match at the
2021 Rugby League World Cup, Waerea-Hargreaves was sent to the sin bin for a stiff arm to the head of Dan Norman during New Zealand's 48-10 victory over the Republic of Ireland.
2023 Waerea-Hargreaves signed a one-year extension with the club for the 2024 season. In round 26 of the
2023 NRL season, Waerea-Hargreaves was placed on report for a high tackle on Wests Tigers player
Apisai Koroisau. Waerea-Hargreaves was later suspended for seven matches, which ended his season.
2024 On 20 February 2024, Waerea-Hargreaves announced he would depart the Sydney Roosters following the season's conclusion. In round 10 of the
2024 NRL season, Waerea-Hargreaves played his 300th game for the Sydney Roosters in their 38-18 victory over the New Zealand Warriors. Waerea-Hargreaves would go outright first for most games played for the club during their round 18 match against St. George Illawarra. Waerea-Hargreaves was sin binned during the game. Waerea-Hargreaves played 18 games for the Sydney Roosters in his final season at the club including their preliminary final defeat against Melbourne.
Hull Kingston Rovers A day after announcing his departure from Sydney Roosters, he had signed for
Hull Kingston Rovers effective for 2025. In April, Waerea-Hargreaves announced he would retire following the
2025 season. On 7 June, he played in Hull Kingston Rovers 8-6
2025 Challenge Cup final victory over Warrington Wolves, winning Hull KR's first major trophy in 40 years. On 18 September, Waerea-Hargeaves played in Hull Kingston Rovers final game of the regular season to claim the League Leaders Shield in victory over Warrington Waerea-Hargreaves ended his career as
treble winners with Hull Kingston Rovers after defeating Wigan Warriors 24-6 in the
2025 Super League Grand Final to claim club's first league title in 40 years and first of the Super League era. ==International career==