Eberl, who played 146 games for Gladbach between 1999-2005, took over the club’s youth and amateur football programmes in 2005. He was appointed sporting director in 2008, and extended his contract with the club in 2020.
His resignation comes during a difficult spell for Gladbach, who have lost seven of their last nine games in all competitions.
“I can understand the people who might question the timing of my decision with the position the club is in,” Eberl said. “But I just don’t have the strength to keep doing this job the way I have for so long.
“I haven’t made this decision in order to move to another club. For now, I don’t want anything to do with football.”
“Today is a difficult day for us, a bad day,” club president Rolf Koenigs said.
“Max Eberl informed us that he no longer wishes to carry on as sporting director. We respected that, although of course we were disappointed, particularly as we had only extended his contract at the end of 2020.”
Gladbach are 12th in the Bundesliga table and next face Arminia Bielefeld on Feb. 5, who are on a five-game unbeaten run.