Northern Ireland international Keith Gillespie has handed in a transfer request but Sheffield United insist they still want to keep the experienced former Manchester United and Newcastle United winger.
The 31-year-old has spent the last 18 months at Bramall Lane and has made 55 appearances for the Blades.
However, he was sent off immediately after coming on as a substitute in Saturday's defeat at Reading for elbowing Stephen Hunt and is set to serve a three-match ban.
United chairman Terry Robinson confirmed the transfer request, but added on the club's official website: "As far as we're concerned contract negotiations are still ongoing."
Gillespie started his career at Old Trafford but, after making only nine Premiership appearances for Sir Alex Ferguson's side, he moved to Newcastle in January 1995 as part of the deal that saw Andy Cole move in the opposite direction.
After making over 100 Premiership appearances for the north-east side, he moved to Blackburn eight years ago in a £2.35million deal.
Gillespie spent two years at Leicester City before moving to the Blades on a free transfer in August 2005.