Cocu pulled no punches about a overall performance that condemned Derby to their worst start to a season due to the fact 1992.
Derby never recovered after three dreams in 4 mins gave Blackburn manage and simplest David Marshall prevented an excellent heavier defeat.
Tyrhys Dolan scored from close range after Ben Brereton hit the post within the 11th minute and previous County midfielder Bradley Johnson smashed in a second from 25 yards a minute later.
Marshall ought to do nothing approximately Johnson’s 2d in the fifteenth minute whilst some other fierce strike changed into deflected past him but he did properly to disclaim Brereton and Adam Armstrong earlier than the damage.
Derby have been better inside the 2d 1/2 and created possibilities however Blackburn scored again within the 77th minute while Harry Chapman broke clean on the right and set up Armstrong for a simple finish.
Cocu became scathing approximately the manner his group performed out of possession.
“Last season we had two bad video games and I examine this a little bit with the ones games because I suppose nowadays a massive a part of our defeat was our attitude, our passion, willingness and preference to guard and track down,” he said.
“You can speak about strategies but in any machine it’s about how you execute it and if you concede 3 goals in four minutes, I suppose that asserts enough.
“We showed some excellent soccer however I am involved about how we gift ourselves whilst we do not have the ball and that is a big a part of the game.
“We had sixty five in step with cent possession, so what do we do after they have the ball? It’s not top sufficient, this is underperforming.
“We always say live in the game, for a few minutes get yourself collectively, take initiative and cross forward again but by using conceding three desires and two similar goals, it’s unacceptable.
“In the second 1/2, the mindset turned into lots better but it’s a bit bit late whilst you are three-0 down and that’s what I’m dissatisfied about because I anticipated we would have learnt from the ones video games of ultimate season.”
Rovers took their desires tally for the season to eleven in 3 video games.
Blackburn manager Tony Mowbray said: “The players deserve big credit score for their work-fee, their attempt and strength they may be setting into the games and have become the rewards for all the difficult paintings we’ve achieved over the last six months when we’ve got attempted to change the crew around a chunk.
“I assume the blessings are there for all to peer. I’m informed we had 23 pictures so to score 4, I assume it’s been one in all our troubles, the percentages. We’ve labored a lot on completing and the final pass into the container and picking the right bypass when we get into vital regions.
“That become some thing that became letting us down, we had been capable of dominate games however no longer finishing teams off due to the fact we were not taking chances but I do not assume you may be too grasping.
“For Johnson to score, it really is outstanding for him. He’s growing into this football club a little bit now, he looks like he is irreplaceable in the intervening time, in the remaining 4 games besides, so let’s see if we are able to preserve it and Bradley can keep it.”