Derby County will be deducted 12 points with immediate effect after the Championship side entered administration, the English Football League (EFL) said on Wednesday.
Derby, managed by former England and Manchester United striker Wayne Rooney, filed a notice to appoint administrators last week amid a financial crisis and announced they had completed the process earlier on Wednesday.
On Thursday, Rooney said he would fight for the club to keep them in the Championship: "I will fight for the club. I wouldn't leave the staff in the lurch. They need someone to lead them."
"If [the deduction] stays at 12 points, I feel we can stay up. No team has ever done that and I have challenged the players to make history.
"If it goes to 21 points, it will be very difficult and it's likely we will be in League One next season."
Last Friday, the club said "a number of developments" led to the decision, including a failure to identify a buyer and the negative effect of the COVID-19 pandemic on revenue streams.
Rooney's Derby, who remain under a transfer embargo, were 12th in the Championship with 10 points from their opening eight games.
The 12-point deduction, the standard penalty for a club entering administration, will leave them bottom of the standings on minus two points, six adrift of their East Midlands rivals Nottingham Forest.
"I appreciate that this is a challenging and concerning period for everyone associated with the club, particularly the staff and supporters, and it is our intention to work proactively with the administrators and all relevant parties with the objective of securing a long-term and viable future for Derby County," EFL chief executive Trevor Birch said in a statement
Derby could still face a separate points penalty for breaching the EFL's financial regulations. They were fined £100,000 ($136,170) by an independent disciplinary commission in July accounting irregularities.