[10] On 22 September, aged 17, he made his Super League debut for the Castleford Tigers against the Leeds Rhinos in the final round of the season.
[11][12] His performance in defeat earned praise from head coaches Danny Ward and Rohan Smith[13] as well as the travelling fans.
[16] In October 2023, Rooney was included in Castleford's listed first-team squad ahead of the 2024 season,[17][18] one of only two fullbacks alongside Luke Hooley.
[22][23] He required surgery for an ankle injury suffered in January,[24] which prevented him filling in for the injured Hooley before the signing of Tex Hoy.
[3] On 1 August, playing as a winger, Rooney made his second senior appearance and scored his first Super League try in Castleford's home loss against Leigh.