"For how good we were last week and everyone singing our praises, we were as bad this week.
"It was an awful display. We made Middlesbrough look like world beaters. We haven't kicked a ball, it is as simple as that.
"We have got our backsides kicked and the best team won."
Bruce could not hide his disappointment but said he had not had to express those feelings to his squad.
"I haven't had to read the riot act because the players know," he added.
"It is hugely disappointing but that is what Premier League football is about.
"I think there was only possibly Cameron Jerome in my team who can come away with any credit."