Temuri Ketsbaia has left Olympiakos just a day before their opening Champions League group game.
Ketsbaia only took charge of the Greek club in May and had signed a three-year contract, but he has lasted just four months in the job.
Olympiakos have made it through two qualifying rounds to reach the group stage of the Champions League, while they have played just two domestic matches.
Ketsbaia has been criticised by supporters and the media and the decision has now been made for him to stand down.
“Olympiakos announces the mutual solution of its collaboration with coach Temuri Ketsbaia,” read a statement on the club’s official website.
“The technical leadership of the team will be temporarily undertaken by Bozidar Bandovic. His assistant will be Andreas Niniadis.”
Ketsbaia became the first man to lead Cypriot club Anorthosis Famagusta into the group phase of the Champions League last season.