Rovers' new owners the Venky's Group dropped the bombshell yesterday afternoon despite the club not looking like going down under Sam’s command.
It is however fair to say that the man who took over in December 2008 has had a mixed bag of results this season, but the team still sit in thirteenth place in the table.
But the 2-1 defeat against Bolton at the weekend proved to be his downfall.
Speaking to Sky Sports News, Nelsen said: "I am devastated for Sam. He had an absolutely fantastic relationship with all of the players.
"Everyone respected him. He took the club out of the doldrums really.
"We were in massive trouble with no money. He solidified us and put us into a top-10 position, and again he did it on a shoe-string."
He added: "I'm just getting over the shock of it. We've got to get over it, but at the moment I want to say, and I can speak for nearly all the players I'm sure, that they will be devastated. He was a very likeable character."