Rotherham's 3-0 Championship defeat by Derby is unacceptable, according to Millers manager Neil Redfearn.
His side have lost three and drawn one of 50-year-old Redfearn's four matches since he replaced Steve Evans at the New York Stadium.
"I accept the odd mistake but not the lack of work-rate and wanting to win and that was apparent today," he said.
Rotherham have only won twice in the league this season and have dropped to bottom of the Championship.
"Players have got to take responsibility," Redfearn continued.
"You put a game plan together and they go out there. It's up to the players to take the bull by the horns, and once we let them get in their stride we never laid a glove on them and that is really disappointing."
Rotherham lost to promotion contenders Derby at the iPro Stadium on Saturday thanks to goals from Andreas Weimann, Jacob Butterfield and Richard Keogh.
"They were worthy 3-0 winners to be honest," said Redfearn.
"We have got a lot of work to do, we have got to bring some players, that's a fact.
"At this moment in time I have got to see more from the players that have got the shirt, there's got to be a desire and will to win.
"We are where we are, we know Derby are a good side, but it has got to be more of a match than that."