The former Malaysia coach has launched a stinging attack on the Norwegian midfielder, claiming that his legs have gone and that the club cannot afford to carry big name players
Pedersen has been at Ewood Park since 2004, making over 250 appearances for the club, but the former Malaysia coach did not hold back in his appraisal of the 30-year-old.
Singh warned that wingers that have suffered a loss of pace are "of no use" if they fail to reinvent themselves and demanded an improvement in the Norwegian's form in a more central role.
"Morten Gamst Pedersen used to be a fantastic left winger," he said at an open fans forum organised by the Blackburn Rovers Action Group. "Unfortunately he has not reinvented himself as a centre midfielder.
"He has lost his legs. He has not been contributing to the team. We want people who can run and run, and keep running for 90 minutes. We are not here to entertain big names. This is why teams fail.
"Under [previous Blackburn manager] Sam Allardyce, he was possibly three years younger. Wingers lose their pace and if they can't reinvent themselves they are, quite literally, of no use.
"There are players who are past their sell-by-date. If this club wants to move forward, you need energy and you need vigour."
As well as Pedersen, Rovers manager Steve Kean was also put under pressure, with Singh saying he would be sacked if the team lost three games in a row.
Blackburn are looking to make an immediate return to the Premier League after being relegated to the Championship last season.