Horsfield was signed by then manager Neil Warnock in February 2006 initially on loan before signing permanently in the summer, he made his debut in the 2-1 victory at Sheffield Wednesday.
However for some unknown reason he fell out of favour at Bramall Lane, rumoured by a changing room bust up. He never played for the Blades again and was last season sent out on loan to Leeds United and then Leicester City.
New Sheffield United manager Bryan Robson, who worked with the Barnsley born striker whilst at the Hawthorns is set to hand his former star a chance at Bramall Lane.
Robson told the Yorkshire Post: "There are a lot of players in the squad who I need to sit down and speak with about where they are mentally. I need to know whether they want to stay or move on.
"Geoff is still under contract and I will need players in the club who are up for the challenge of getting us promoted."