Heidel, who took over at Schalke in May 2016, had a contract valid through June 2020. The club says, "The supervisory board complied with this request (to step down) and will ensure that a speedy solution is found for the sporting reorganization."
The 55-year-old Heidel was reportedly receiving criticism inside Schalke for transfer dealings. Domenico Tedesco, a young coach Heidel appointed, was lauded last season for leading Schalke to second place in his debut campaign, but he has failed to build on that success with the club currently 14th in the 18-team division.
Schalke's tally of 23 points from 23 games is its worst since it had 16 at the same stage in 1982/83, when it was relegated. Heidel says, "We've failed to reach expectations in the Bundesliga for a variety of reasons. Even if a lot has gone against us this season, I naturally have overall responsibility for it."
More AP German soccer coverage: https://apnews.com/Bundesliga and https://twitter.com/AP_Sports