Peterborough manager Graham Westley described his side's performance in the 2-0 loss at Fleetwood as "appalling".
The result left Posh closer to the relegation zone than the play-off places and ended the team's three-game winning streak.
"I won't tolerate what I've watched tonight," Westley told BBC Radio Cambridgeshire.
"The most energy we put in was smashing up the noticeboard in the dressing room after the game."
Relegation strugglers Fleetwood had gone six league games without a win in the league before Tuesday's game.
"We didn't run hard enough, they ran harder than us. We didn't play with enough quality, they showed more quality than us. We deserved what we got," Westley added.
"I thought that performance was an insult to the people who travelled here to watch us.
"We're at that stage of the season where it's decision-making time. We've seen too many people too often produce the goods one week and produce inconsistency the next."