Fortune, 31 was signed by Kevin Blackwell on a free transfer from Charlton Athletic in September 2009 - he made debut two months later in a 2-2 draw at Barnsley and netted his first (and only) goal in the 3-0 demolition of Reading in the few appearances he made for the Bramall Lane club.
He was drafted in as a squad player as cover for Chris Morgan and Matthew Kilgallon and played mostly in the reserves; he left the Lane in August 2010 having made four (+3) appearances for the Blades where he re-joined Charlton on a free transfer.