Coach Paul Grayson has apologised to Essex supporters for their "shambolic" innings defeat to Northants last week.
Essex were skittled out for 183 in their first innings, but looked back in it when they reduced the hosts to 171-8.
But their bowlers, without the injured David Masters, then bowled too short and wide and allowed the Northants tail to plunder a further 228 at a rate of more than six an over.
David Willey (78 off 78 balls), Steven Crook (88no off 104), and Trent Copeland (70 off 67 balls) destroyed the bowling of Reece Topley, Maurice Chambers and Tymal Mills.
Northants then bowled Essex out for 208 - Willey taking five wickets - to complete victory by an innings and nine runs with a series of dreadful shots not helping the visitors' cause.
Grayson said: "As Head Coach, I feel that I wish to publicly express my apologies to all members and supporters for the shambolic performance produced by the Essex players that resulted in an innings defeat at Northamptonshire last week.
"At one stage on day two with only two first innings wickets intact, our opponents were still trailing by 12 runs but by the time the final two wickets had been claimed, they had forged a lead of 216 runs.
"We then generally batted poorly to add to the obvious shortcomings in the bowling department, all resulting in a defeat by a highly embarrassing margin.
"I feel that it is right that our members and supporters should be aware that the players have been told in no uncertain terms that their performance, as a team, was totally unacceptable and will not be tolerated.
"I can assure you that changes will be made for the next match that starts on Monday week against Hampshire at Chelmsford.
"I feel that it is important to stress to our members and supporters that I, and the coaching staff, will continue to do everything in our powers to bring success to this club but the players have, of course, a major part to play if that desire we hold is to be realised.
"The coaching staff have every confidence in the potential of the squad and we will continue to all work together to get our season back on track."