Sheffield United are eyeing Kilmarnock fullback Stephen O'Donnell.
The Daily Mail says Middlesbrough, Derby County, Stoke City and Sheffield United are all interested in the Scotland right-back.
The 27-year-old has 12 months remaining on his Killie contract and the board at Rugby Park could be tempted to cash in on one of their prized assets.
New manager Angelo Alessio expressed concerns over his ability to hang on to the club's best players after O'Donnell, Greg Taylor, Stuart Findlay and Eamonn Brophy were all included in Steve Clarke's first Scotland squad.