Sabri Lamouchi was left frustrated that the same mistakes ultimately cost Nottingham Forest as they suffered defeat against Bristol City.
The Reds fell behind to two goals within the first 25 minutes but showed a positive reaction after that to work their way back into the game.
Luke Freeman reduced the arrears but several fine saves by City goalkeeper Daniel Bentley kept The Reds out and it came down to the poor start which proved costly.
Speaking after the game, Lamouchi said: “It was a different game but the same mistake, it is unacceptable to only start playing in the second half. We should play the whole game like that, from minute one with the same spirit as in the second half.
“We created a lot, fortunately we scored but unfortunately not enough to come back into the game and put them under more pressure, but it was easy for them to play against us and to score.
“This is not Forest, this is not professional and we need to wake up and to understand that everyone needs to take responsibility.
“I am sorry to say that but new players, new team, this is it. We are professional and we need to do our jobs. On the pitch we need to run, to fight and to respect the plan.
“To play like that, to not win the second balls or the duels and to make easy mistakes is easy for the opponent, to come to The City Ground and score and keep the result until the end.”