Rotherham United boss Lee Clark has questioned the application from his players after they were relegated from League One.
The Millers lost 3-0 at Wigan on Tuesday to confirm their demotion to the fourth tier.
They have now won just three of their last 27 league matches.
"There's lots of negatives about the whole squad. What I've walked into has been a real eye-opener and very sad to be honest," Clark told BBC Radio Sheffield.
"I've tried everything and we've worked so hard in terms of tactical sessions and work on the training ground.
"We had to go to the stadium this afternoon to go through some tactical work because I couldn't pick a team yesterday, because some players were calling in sick and some saying they weren't 100% fit. It's the same every day.
"We're not a robust squad, we're not a fit squad and we haven't got the fire in our bellies, with some exceptions."
Clark added: "Let's get it right, they've cost a man who loves this club his job before me.
"He would have done everything for this club and he lost his job, and if it's happening to a second manager, then it's what's going on behind the scenes."
Clark took over from Matt Hamshaw last month, but has taken just one point from his five matches in charge so far.
The former Huddersfield and Birmingham boss had been out of football for four years prior to taking the job until the end of the season.
Despite how badly the results have gone, Clark says the spell has given him back his love for the game and he has not ruled out staying on.
"I came back into the game because I love football and this has hurt us but it has given us me spark back," he said.
"I want to stay in football.
"There hasn't been that turnaround in results, but there has been mitigating circumstances."
Clark added: "Whoever is the manager of the club has a huge job but a good one because he has the opportunity to reset and give these Rotherham fans, who are fantastic people, a team they deserve."
