Elite performance director Graeme Welch accused Derbyshire's players of lacking "bottle" in the 222-run defeat by Surrey in the County Championship.
Derbyshire were dismissed for 125 in their second innings and lie sixth in Division Two, while Welch's side are also bottom of the T20 Blast North Group with six losses from eight games.
"We have had opportunities in games which we have showed no fight and no bottle," he told BBC Radio Derby.
"That is the most disturbing thing."
Welch described the loss to Surrey at the County Ground as "one of the worst he has seen" since taking charge.
"The senior players have let themselves, their team-mates and the club down," Welch said.
"There have been a few harsh words said and few a things said that people did not want to hear. We will see where we go from here.
"These lads have got everything they need so they need to look within. They need to look at themselves in the mirror as all us management do every day.
"They need to fight harder. There are lads with a lot of experience and they have to look in the mirror."