*Club domestic league appearances and goals, correct as of 00:15 22 July 2023 (UTC) ‡ National team caps and goals, correct as of 21:13, 17 November 2024 (UTC)
Mullins signed for the youth academy of Brighton & Hove Albion from Bohemians in January 2023 for an undisclosed fee, signing a two-and-a-half-year contract, until 2025.[8] The first-team pathway granted to Evan Ferguson, who also made the switch from Bohemians to Brighton, was said to be a factor in the decision to move.[9]