The Black Country side started the season well, but have mustered just one point from their last five games.
The last of those matches was the 2-0 defeat to Huddersfield at the weekend, with Nuno admitting he was surprised by his side's insipid display.
"It was a big disappointment, a bad performance," he told the press. "We were not able to play the way we usually do.
"Credit to Huddersfield but clearly it was a very bad performance from us, individually and collectively as a team. There were too many mistakes.
"We are not in a good moment. How we analyse it is based on the last performance. It is very poor, five games and just one draw.
"There were a couple of good performances, some bad, and we go and see where we can improve.
"There is no point staying on the past. How do we deal with that? Game by game, training session by training session. We must perform to the standards we are used to."