Bill Brelsford came from a footballing family, two brothers playing for Sheffield Wednesday, but he made his league début with Doncaster Rovers. In 1910 he transferred back to his home town Sheffield but he did not join his brothers at Wednesday, joining cross-city rivals Sheffield United instead. He was a member of the Blades team who won the FA Cup final in 1915 where it was reported he broke up many of the Chelsea attacks by heading the ball back towards their half.