Peterborough have announced the departure of manager Dave Robertson with immediate effect.
Robertson was dismissed in the wake of Saturday's 2-1 defeat at Southend which left them 20th in League One.
In a statement Posh chairman Darragh MacAnthony said: "I would personally like to thank David for stepping in last season when the club was at a low point after the previous manager's departure.
"He steadied the ship, put a smile on everyone's faces again and worked tirelessly each day to improve the club's fortunes on the pitch.
"Unfortunately after yesterday's result and the manner of defeat, I felt it was time to take action and make a change as it had become plain to see our young squad was under-performing and playing nowhere near their potential.
"Make no mistake, our players must also shoulder responsibility for this awful start to the season which has now led to a great person losing their job."
Robertson had replaced former boss Darren Ferguson in February, initially in a caretaker capacity, before being given the job on a full-time basis in May.
Among those defeats suffered this season, Peterborough, who were expected to mount a promotion challenge, were beaten 3-1 by Sheffield United thanks to a double from Conor Sammon and another by Jose Baxter.
The betting on who will take over from Robertson at London Road has set former Sheffield United manager Nigel Clough and current Rotherham United boss Steve Evans as early favourites (6-1 with SkyBet). Ex-Blade Stuart McCall, who spent the tail end of last season at Rangers, is 20-1 while former Owls managers Alan Irvine and Gary Megson are also mentioned, albeit at 25-1.