"He was not rated by the fans in Munich," said van Gaal on Bavarian television. "In such a case, it is better to let the player go and leave the club.
"Edson is an excellent defender. He has just been unlucky here.
"I really hope the fans in Glasgow help him."
Bayern also offloaded Luca Toni, Andreas Ottl and Breno during the winter transfer window, but did not make any new signings themselves.