His assistant Craig Bellamy has been placed in temporary charge while the club identifies a permanent replacement, with Mike Jackson his number two.
But who will get the job on a full-time basis?
(Odds were correct at the time of writing)
1. Alexander Blessin - 33/1
The German is currently in charge of Belgian side Union SG, where he boasts a 62 per cent win rate. Finished second in the Belgian Pro League.Photo: Ahmad Mora
2. Ashley Cole - 33/1
The former Chelsea and England left-back is currently on the coaching staff at Birmingham City, while he's also assisted Lee Carsley with England's Under-21s.Photo: Ashley Allen
3. Bo Henriksen - 33/1
The Danish coach has only been at Mainz since February, where he’s enjoyed a 46 per cent win rate. Previously managed Midtjylland and FC Zurich.Photo: Selim Sudheimer
4. Thierry Henry - 33/1
The Arsenal legend is currently in charge of Maxime Esteve and Wilson Odobert with France’s Under-21 side. Previously managed Monaco and Montreal Impact.Photo: Stuart MacFarlane