Guy Whittingham was sacked as manager of League Two side Portsmouth because confidence had "drained" from the team, says chief executive Mark Catlin.
Former Pompey striker Whittingham, 49, had his contract terminated on Monday after a year in charge at Fratton Park.
Catlin told BBC Radio Solent: "The team had completely lost confidence.
"It seemed to drain out of the team. As it drained out of the team, it drained out of the supporters as well and we just can't have that."
Whittingham was sacked with Portsmouth 18th in League Two and Catlin said he told the former Sheffield Wednesday player "expectation levels would rise" as the board gave him financial backing.
"We started off with a mid-table budget and now we have a borderline play-offs budget," he added.
"Where we are now is not good enough. We're nearer to relegation than we are to the play-offs."
Andy Awford, another ex-Portsmouth player, took caretaker charge for Tuesday's 2-1 home defeat by Southend.
And Catlin said the club would look to start interviewing candidates for the manager's position by the middle of next week.
"We have got a shortlist in mind with people we think could fit the role, plus, when the CVs come in the names can sometimes blow you away," he added.
"People like challenges and I don't think there's a bigger challenge than getting Portsmouth back to where we all think it should be over the next four or five years."