Sheehan, 27 is out of contract this summer at the Meadow Lane club who only just survived their battle against the drop from League One on the final day of the domestic season. He has been offered a new deal by County boss Shaun Derry but Sheffield United boss Nigel Clough looks to have targetted him out as a potential candidate as a left-back.
The Galway born defender may opted to commit himself to another season in Nottingham having picked up the Suppporters' Player of the Season award, however it is understood that Tottenham Hotspur defender Kevin Stewart is also being targetted by the Blades as Mr Clough looks to strenghen his back four for next season.