Paul Keegan admits players performing their roles in training is no use if they do not take it into a game on a Saturday.
Doncaster Rovers were poor as they fell to a 1-0 defeat to neighbours Sheffield United.
Midfielder Keegan said there were no excuses for the performance as every player knew his role.
“We worked on it in training all week and everyone knew their jobs,” Keegan said. “We all knew what we were supposed to be doing but you’ve got to do it on a Saturday.
“We couldn’t have been any more prepared for the game.
“But we didn’t take the gaffer’s instructions on.
“Our shape wasn’t right. We were off the pace and we couldn’t get near their players. Our quality wasn’t good enough.
“It was a bad day for us.
“It’s obviously very disappointing with a big crowd, a derby game.
“These are the best games of the season for us. We look forward to them but it just wasn’t good enough.”
Rovers have another derby match next weekend when they travel to Barnsley.
And Keegan says the work begins on Monday to right the wrongs of defeat to the Blades.
He said: “We’ve got to go again. We’ve got another big game coming up on Saturday.
“We’ve got to put it right in training but more importantly we’ve got to do it on a Saturday.”