His side were once again susceptible to set-pieces as they lost 3-2 at Cardiff City and slipped to fourth in the Championship .
And the boss said: "If you score two good goals away from home, you don't want to end up with nothing.
"This hurts and it's disappointing but we know exactly what went wrong.
"It was also what went wrong in the previous two away games.
"Our trust, attitude and belief was good, but we again conceded to set-pieces and for this we can only blame ourselves.
"It's not a problem as a group, more down to individual one-against-one challenges.
"Players have to stay focused and concentrate and be really hungry to defend against their opponents.
"It's not always the same players, and it's something we have to change."