The Tigers remain in an automatic promotion place despite seeing their four-game winning run disappear as they drew 0-0 with Leicester.
And his side's lack of ruthlessness in front of goal is frustrating, and beginning to concern, him.
"The big chances - we should be scoring," he said. "Anyone who has seen us over the past four or five months will know that's the frustration.
"In big games especially, you can't be expected to create eight or nine chances.
"Today we've had four or five. Really we've got to take one of them in a big game.
"It's gnawing away at us all. It's not just the goalscoring it's all round we've got to contribute.
"Look at Abdoulaye. I'm shouting 'goal' as soon as I see him with that big head three yards out coming towards it.
"You think it's in the net. It's all round that the chances have come. I hope it's not going to be our Achilles heel."