Jon Whitney issued an apology to the 280 travelling supporters after the Saddlers’ 5-1 defeat at Rotherham.
The Millers led 4-0 after 31 minutes, thanks to braces from Lee Frecklington and Jon Taylor.
Amadou Bakayoko pulled one back at the start of the second half but Frecklington added a fifth to complete his hat-trick late on.
“For 30 minutes of the game, we didn’t compete,” said Whitney. “We didn’t do the basics of football and allowed them to put the game to bed.
“The first goal, it was one of those – a worldie. But the other three goals in the first half, we’re not happy about.
“I apologise to the travelling supporters tonight.
“We didn't play anywhere near the standards we’ve set over the previous five weeks. You can’t shy away from that.
“They’ll have to come in in the morning and be accountable. If your player has headed the ball, or you haven’t done your job, you’ll have to be ready for some criticism.
“As a group, we were well below par tonight and there are no excuses for that. We weren’t good enough.”