His contract expired last season with the Blades and he also played parts with Halifax, Scarborough, Fulham, Birmingham, Wigan, WBA and loan spells with Leeds, Leicester and Scunthorpe.
He revealed his battle in the Daily Mirror. He said: "I was diagnosed last Friday and I'm going in for surgery next Thursday. The surgeon has told me that this is the end of my professional career, but that's at the back of my mind now.
Blades Mad would like to offer our best wishes to Geoff and hope he has a speedy recovery.