Cardiff boss Dave Jones pointed his finger at his leaky defence after a disappointing 1-0 defeat at Middlesbrough.
Boro, whose backline had to cope with the absence of suspended centre-back David Wheater, got their only goal through a first-half Julio Arca penalty, converted after Gabor Gyepes brought down Marvin Emnes in the box.
Jones said: "I don't know how often we are going to leave the door open at the back. A bit of fear has crept in there somehow. At the moment that unit isn't working."
He added: "We are the second biggest scorers so there is nothing wrong going forward but if you don't score you have to keep a clean sheet and that isn't happening and too often we end up chasing the game.
"I wouldn't mind if we were beaten by good movement but it was a punt down the middle and a sloppily conceded penalty and that shouldn't happen.
"We have to make sure we don't get carried away and let a blame culture creep in but right now they need a bit of criticism. It is harsh but they have to accept it."
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