Lincoln City manager David Holdsworth questioned the attitude of some of his players following their 1-0 Blue Square Bet Premier defeat by Alfreton.
It left the Imps without a win in six games and they are now only three points above the relegation zone.
Holdsworth told BBC Lincolnshire: "I'm sick to death of letting in soft goals.
"If you can't keep a clean sheet you won't win. People need to stand up and be counted and if we don't feel they're up for the fight then they won't play."
The Imps created more chances than Alfreton but Jake Moult's 45th-minute strike proved decisive for the Reds.
Holdsworth added: "I'm not saying players don't care but it has to hurt to lose."
And he hinted that he had already earmarked some players for departure the end of the season.
"I care about this club, I care about the fans and everyone involved in the club and there are certain factors which have got to change," he said. "That may take some time and it may take until the summer.
"We are in a relegation battle but we've brought in some players who wear their heart on their sleeve, who care about the club and would like to stay.
"I would imagine you could earn more in a supermarket than some of these boys are earning, but there are some who are on big wages and I'd like them to earn that."