"We didn't play the same way they did," Karanka told BBC Tees.
"They were fighting for every ball as if they were fighting for their lives and we haven't had the same desire."
Despite the loss, Karanka refused to be too downbeat and believes his side can learn from their mistakes.
"We could have won by four or five goals but instead we lost," he added.
Looks like he can't get the desire he wants from his squad