Signing from Scottish Premiership side Hibernian, the centre-back made 85 appearances for Hibs across domestic and European competition. Born in Dublin, Warren came through Bohemians’ academy, making his debut as an 18-year-old. He joined Brighton & Hove Albion in January 2018, gaining experience on loan at MK Dons, making the move permanent in January 2021 and totalled 177 appearances for the Dons.