Chelsea chief executive Peter Kenyon has revealed that Jose Mourinho's departure was not planned and came about only as a result of a meeting on Wednesday evening.
Kenyon also confirmed that the appointment of Avram Grant was a permanent one, although no contract with the Israeli coach had yet been agreed.
He also denied newspaper reports suggesting an argument between Mourinho and John Terry had hastened the Portuguese's departure.
Kenyon said: "There's absolutely nothing in the stories going around and in particular no truth in any rumours of a bust-up with one or several players which led to him leaving the club. That is incorrect and we need to move on.
"We had reached the point through the last few days whereby it was right for the club and him to mutually agree to part company.
"We are not going to talk about the specifics of those meetings. They have been well reported, some of the issues.
"What did change over the last week to 10 days, through discussions with Jose, was that in order to ensure the club moved forwards that was (Mourinho's departure) the right decision.
"It has been addressed properly and professionally and now it is time to move on."
Blues chairman Bruce Buck added: "It has been a very eventful few days but it was very important for the club to announce Avram Grant and Steve Clarke as soon as possible.
"We are all committed building on our strengths and build on Jose Mourinho's achievements. We firmly believe they can help us do that.
"I am particularly thankful to Jose for giving the club a winning spirit and we want to extend that further.
"I don't believe this is a backward step. I believe this is a step forward. We've spent an awful lot of time with Avram and know Steve very well, they both share our vision."
Grant is looking forward to his new role, saying: "I'm a person of my own. I've taken all my decisions in football on my own. If we lose, it's down to me.
"I have full respect for what Jose Mourinho did in the past and I want to follow this success and make things of my own. But football is also entertainment. We need to win games and win trophies but we need to play positive football."