In 2021, Walsh joined the Brisbane Broncos NRL squad on a development contract.[8] He began the season playing for the Norths Devils in the Queensland Cup.[9]
On 18 March, Walsh signed a three-year contract with the New Zealand Warriors, beginning in 2022.[10][11] On 10 April, he was released early from his Brisbane contract to join the Warriors immediately.[12][13]
On 25 April, in round 7 of the 2021 NRL season, Walsh made his first grade debut for the Warriors against Melbourne.[14]
In May, Walsh confirmed his allegiance to Queensland and Australia over New Zealand.[1] It was confirmed on 21 June that he had been selected to play as fullback for the Queensland Maroons for the second game of the State of Origin series.[15] At 18, he would have been the youngest player to be selected in the Queensland team since Ben Ikin in 1995, however he was ruled out due to an injury.[16]
In round 23, Walsh had a disappointing afternoon with the goal kicking duties only managing to convert one goal from five attempts, including a conversion attempt near the touch-line late in the game which would likely have sent the game against Brisbane into extra-time. New Zealand lost the match 24-22 which effectively ended their already slim chance of reaching the finals.[17]
Cocaine possession
On 25 September 2021, a video emerged of Walsh being arrested by police at a Surfers Paradise nightclub. The following day, Walsh addressed the media and said that he had failed a previous move on order by the police. He then went on to say “I didn't move on. That led to me getting arrested and taken back to the police station. Once I got back to the police station I got searched and I was in possession of a small bag of cocaine – which I had some during the night.
"No-one else is involved in this. It is solely on me. I put my hand up – I should never have done it. It is a mistake I made. I want to say sorry to sponsors, fans, the Warriors".[18] He was handed a $5000 fine and suspended for two matches over the incident.[19]
2022
On 20 June, Walsh was selected in the extended Queensland Maroons squad for State of Origin Game 2, however did not play.[20]
On 6 July, Walsh was granted an early release from his New Zealand contract to re-join his former club Brisbane starting in 2023. Walsh cited a relationship breakdown as the reason for the move. He had also reportedly turned down a $2.8 million offer from new NRL franchise The Dolphins in favour of signing with Brisbane.[21]
On 7 July, Brisbane officially announced his return to the club, on a three-year deal.[22]
2023
On 1 January, it was reported that Walsh became involved in a verbal altercation with Gold Coast player David Fifita. The pair needed to be separated by security staff at Burleigh Heads. In the pre-season trials, Walsh suffered a facial injury in Brisbane's match against the Gold Coast and was ruled out for an indefinite period.[23][24]
In round 2 of the 2023 NRL season, Walsh made his club debut for Brisbane and scored a try in their 28–16 victory over arch-rivals North Queensland.[25]
The following week, he scored two tries in a 40–18 victory over St. George Illawarra.[26]
After a series of good performances, Walsh was selected to make his debut for Queensland in game one of the 2023 State of Origin series, replacing incumbent fullback Kalyn Ponga.[27]
Walsh was involved in an altercation with New South Wales five-eighth Jarome Luai in the final minutes of game two of the State of Origin series, resulting in both players being sent off and New South Wales winger Josh Addo-Carr being sin-binned. Queensland won the game 32–6, and henceforth the series.[28]
In June 2023, Walsh was suspended for three matches for contrary conduct towards a match official, after saying "What the fuck do you mean, cunt?" directly after referee Chris Butler blew an obstruction penalty in the Broncos' round 17 loss to the Gold Coast Titans. Walsh claimed this was aimed at teammate Patrick Carrigan. As a result of the suspension, Walsh missed the third State of Origin match.[29]
On 29 September, the NRL integrity unit were reportedly investigating Walsh for a verbal altercation he had with a Penrith supporter at Sydney's Darling Harbour. It was alleged that the supporter yelled at Walsh “Moses Leota will take your head”. Walsh responded with “I’ll take your mum’s”.[30]
Walsh played a total of 22 games for Brisbane in the 2023 NRL season. Walsh played in Brisbane's 26-24 loss against Penrith in the 2023 NRL Grand Final.[31]
2024
In round 3 of the 2024 NRL season, Walsh was taken from the field during the clubs grand final rematch loss against Penrith after colliding with Taylan May. It was later announced Walsh would be ruled out for potentially six weeks with a facial fracture.[32]
On 26 March, it was reported that Walsh signed a five-year extension deal worth $5.5 million, making him the highest paid player in the club's history.[33]
In round 8 of the 2024 NRL season, Walsh scored two tries for Brisbane in their 34-10 victory over the Wests Tigers.[34]
Walsh played 14 games for Brisbane in the 2024 NRL season which saw the club miss the finals finishing 12th on the table.[35]
In October, Walsh was placed under investigation by the NRL after an alleged altercation with a fan in Bali.[36] On 31 October, Walsh re-signed with the club on a four year deal.[37]
