Contract negotiations with a number of Blades players are underway, Nigel Clough has confirmed.
Speaking ahead of Friday's Sky Bet League One trip to Port Vale, the Gaffer revealed that United have already spoken to three current players about extending their stays.
On Ryan Flynn, whose current contract expires in the summer, Clough remarked: "We have held talks with Ryan and his representatives and we think that we are very close to agreeing a new deal.
"We are in a good position in terms of a lot of our players being under contract, but, obviously, you don't want to lose your better players and that is why we have moved to try and tie the likes of Ryan down long-term."
Clough also indicated that extending the contract of Bob Harris is also a possibility with the Gaffer keen to keep the Scottish left-back beyond the next 12 months. "We have got a one-year option on Bob, completing that is a formality, and we might even look to sit down over the summer and do something longer term," added Clough.
Negotiations have also started to encourage Harry Maguire to sign a longer contract, with the Blades chief adding: "Harry is a local lad, a home bird, who loves playing for Sheffield United, so all the signs are positive on him, too.
"People probably forget how young Harry is because he has been in the team for so long and has racked up so many games, but he is still developing and his best years remain ahead of him, which we hope will be with us."