The former England Under-21 international was signed by Preston last summer after being released by The Blades (following there Play-Off Final defeat) and left Deepdale in January 2013 after failing to hold down a first team place, making a total of 16 appearances.
He initially signed for United on loan (from Stoke City) in March 2010; making his debut in a 1-1 draw at Doncaster Rovers and in the summer made a full free transfer to the Blades, he was part of the squad which was relegated from the Championship and he missed the vital spot kick at Wembley last season which could have seen us back there. During his time with the Blades he made 106 (+2) appearances.
His signature was confirmed when he tweeted: "Now that it's official!! Cannot wait to get going @dundeefconline looking forward to my time up there!!"