Rooney also labelled Morris disrespectful for the way he has conducted himself, saying the owner hadn't made the effort to speak with him for more than six weeks.

The Rams officially entered administration earlier this week, triggering an automatic 12-point deduction that sunk them to the bottom of English football's second-tier Championship, with the possibility of further points being taken away hanging over the club.

Rooney hit out at Morris in his Thursday press conference for the way the businessman delivered the news and subsequently handled the situation.

"In my opinion, it wasn't sincere enough, it wasn't heartfelt enough, and it wasn't done with enough honesty. Obviously he has moved on and we have to move on and put Mel Morris to the back of our minds," Rooney said.

"I personally haven't spoken to Mel Morris since August 9. I still haven't had a one-on-one conversation, no phone call, no text message. Nothing.

"I find it a bit disrespectful, to be honest. Communication is so important, whether it's good news or bad news, so we can deal with it.

"He's put a lot of money into the club, and he deserves a lot of respect for that, but there are ways of handling things and it has left me disappointed."

Morris said the club had missed out on Stg 20million ($A38 million) in lost revenue as a result of the pandemic and the administrators confirmed Derby's debts run into "the tens of millions of pounds" without disclosing the exact figure.

Earlier on Thursday, the administrators offered hope to the club's supporters and said they are confident of finding a buyer by the end of the year.

Rooney, who last week said he had only heard about the likelihood of Derby going into administration from TV reports, insisted he will not walk away from his job.

The former Manchester United and England striker took interim charge of the club last November following the departure of Phillip Cocu before his permanent appointment two months later.

Rooney, who helped Derby avoid relegation to League One on the final day of last season, admitted he probably would not have taken the job had he known about the club's financial problems.

"I will fight for the club. I wouldn't leave the staff in the lurch. They need someone to lead them. I am committed to this football club," he said.

"I grew up on a council estate in Liverpool and I know how tough life can be ... I care about the players and the staff. What kind of person would I be if I walked away and put my feet up or went on holiday for a few weeks?"

Australian Associated Press