On Saturday the team will play Halmstad BK, which are just one point ahead of Djurgården in the league.
The anonymous letter to Stefan Alvén threatened that if he did not resign before that match, he and his family would face "reprisals", which according to Swedish Radio Sports department was equivalent to death threats.
"It is done by petty people who have no courage, who do not dare to stand for what they think," says Tommy Jacobsson, chair of Djurgården. He does not think the treats come from any real Djurgården fans.
"It is done by petty criminals. I really hope they can get hold of these people so their names can be pinned to the board so everybody can see who they are," Tommy Jacobbson told Swedish Radio's Sports Department.
Earlier in the week, it was announced that Alvén would get a new position which included more administrative work, but on Wednesday the announcement came that he will step down as sports director completely.
These threats come just 8 months after the coach of another Stockholm-based team, Michael Borgqvist of Hammarby, resigned after receiving anonymous threats.