Norwich chairman Ed Balls says Alex Neil's sacking is the beginning of a clearout as they prepare for a Premier League promotion push next season.
Balls said a "miracle" is needed for them to go up this term and Neil's successor will oversee "big changes".
"We're determined to give everything we can to get back to the Premier League, that means planning now for next season," Balls told BBC Radio Norfolk.
Speaking before Saturday's Championship home game against Blackburn, the former shadow chancellor continued: "We need to be up and running now for the beginning of the closed season, for the transfer window. We need to get a new football structure in place.
"The question we needed to ask was, is Alex Neil the right man to take us into next season? We decided yesterday that the answer to that was 'no'.
"The issue now is, can we beat Blackburn? Is the structure that we are going to put in place for next season going to work?
"Who is the right manager to bring into this football club? Can we be up and running in May and June to make what will be quite big changes on the playing side?
"Can we use second-year parachute payments to get back to the Premier League? That is what matters."
Neil's departure from Carrow Road followed a 5-1 thrashing at Sheffield Wednesday and a draw with relegation-threatened Bristol City at Ashton Gate.
"Those games taken as a whole basically meant that baring a miracle, it is not impossible, but barring a miracle we are not in the play-offs this season," Balls said.
"I have sympathy for Alex Neil because he did some great things for this football club," said Balls.
"When he went into the press conference he went in as manager of Norwich City Football Club doing a scheduled press conference. There had not been a board meeting, no decision had been made at all, it hadn't been discussed.
"We sat down after that and we asked ourselves the long-term questions, made a decision and then told Alex straight away.
"It was never going to be a nice thing to do and never be a good time. He took it with great professionalism and dignity."
"A lot of fans were saying make the change and we thought hard about it in December and decided that he was a really capable manager, he had turned things around in a season before and he had the confidence of the players in our judgement," Balls added.
"We tried to do right longer-term thing for the club in December and think we have done the right thing now."