He was sold to Sheffield United for 'a substantial sum' in October 1924 as the Blades sought a replacement for regular left back Ernest Milton. Birks initially failed to settle at Bramall Lane however and missed out on a place in the 1925 FA Cup Final with the ageing Milton being preferred. Never a fully established first team player, Birks did give good service to the Blades during his time playing over 200 games in all competitions.