Manager Keith Curle says members of the Carlisle United squad "don't deserve to be professionals", after Saturday's 3-1 defeat by Accrington Stanley.
Curle's side have gone five games without a win in League Two to continue their struggle against relegation at the bottom end of the table.
The Cumbrians are two places and three points above the relegation zone.
"The strength of character in that changing room is alarmingly weak," Curle told BBC Radio Cumbria.
"You've got to be accountable for yourself and have pride, there are players who can't say they care they put in a performance that shows they don't.
"They are players who don't deserve to be professionals. They are weak."
Five games remain for Carlisle, who were relegated from League One last season, to avoid an unwanted back-to-back drop - this time out of the Football League.
However, Curle has little confidence that certain sections of the squad are capable of helping results improve, given their performances and reaction in recent games.
"There's no spirit in this changing room," Curle continued.
"As individuals, players in that changing room whose accountability for themselves in their profession is weak.
"It's a time where people need to grow up, there's a naivety, a softness, a lack of care and passion.
"You walk in that dressing room, things are happening and players are not doing anything about it, they're allowing other players to make mistakes."
Curle ponders open forum
Carlisle supporters showed their disapproval at the ground and to BBC Radio Cumbria's post-match programme, and Curle is considering tapping into their energies to inspire some passion from his players.
"I might get 50 supporters to come down, have an open forum and through Andrew Jenkins they can have half an hour with the players," Curle said.
"They can tell them exactly what they think of them, and they'll have to take it. Supporters can see when people aren't giving everything for the shirt."