Edgar joined Birmingham last summer having been released by the Clarets, and was a regular in the side under manager Lee Clark. However, things changed when Clark was sacked and replaced by Gary Rowett.
He was no longer involved so much and in January of this year moved to Huddersfield on loan for the remainder of the season where he made 12 league appearances, nine of them starts.
Today he's gone on loan to Sheffield United in a deal that will run until 8th May of next year, although that will be extended should they reach the play-offs. There is no recall option whatsoever for Birmingham.
After completing the signing of Edgar today, Blades' boss Nigel Adkins said: "David is the captain of Canada and has got plenty of experience at a higher level, including winning promotion to the Premier League with Burnley.
"He is 6ft 2in, a big presence and his versatility will be useful as he can play at centre half or in central midfield."
Edgar will be out of contract at Birmingham next summer so it is very likely that he's played his last game for them.
He joined Burnley six years ago after promotion to the Premier League but had to wait until January 2010 for his league debut when, with all of Clarke Carlisle, Steven Caldwell and Andre Bikey unavailable, he played in the side beaten by Man United at Old Trafford.
He went on to play a total of 99 league games for us of which 74 were starts. His most productive season came in 2011/12 when he was first choice centre half throughout the season and started all but two of our Championship games.