Here, we look at the potential ins and outs at Bramall Lane.
5. Jake Wright
The dependable defender recently returned from a loan spell at Bolton Wanderers and is free to leave again Photo: Simon Bellis
6. Axel Disasi
It seems very unlikely at this stage but United have previously been linked with the Reims defender Photo: FRANCOIS NASCIMBENI
7. Luke Freeman
Again this one seems unlikely but yesterday's arrival of Sander Berge has increased the competition in United's midfield Photo: Shaun Botterill