Derek McInnes has left Aberdeen after eight years in charge at Pittodrie, according to reports.
McInnes took over in March 2013 and steered the Dons to their first trophy in two decades with their League Cup win the following year.
But despite also leading his side to four second-placed finishes, pressure began to mount after a series of poor performances this season.
Aberdeen are currently fourth in the Scottish Premiership table, three points behind third-placed Hibernian but having scored just once in their last 10 games.
The 49-year-old's last match in charge of the club was another frustrating goalless draw at home to Hamilton on Saturday.
Former Rangers midfielder McInnes was linked to a return to the club to replace Pedro Caixinha in 2017, while he also rejected a chance to move to Sunderland.
Aberdeen were not immediately available for comment.